Detection rules › Sigma

Sigma rules: 0j

Access To Browser Credential Files By Uncommon Applications - Security

#
Status
test
Severity
low
Author
Daniel Koifman (@Koifsec), Nasreddine Bencherchali
Source
github.com/SigmaHQ/sigma

Detects file access requests to browser credential stores by uncommon processes. Could indicate potential attempt of credential stealing This rule requires heavy baselining before usage.

MITRE ATT&CK Coverage

Telemetry Coverage

Rule Body

title: Access To Browser Credential Files By Uncommon Applications - Security
id: 4b60e527-ec73-4b47-8cb3-f02ad927ca65
related:
    - id: 91cb43db-302a-47e3-b3c8-7ede481e27bf
      type: similar
status: test
description: |
    Detects file access requests to browser credential stores by uncommon processes. Could indicate potential attempt of credential stealing This rule requires heavy baselining before usage.
references:
    - https://ipurple.team/2024/09/10/browser-stored-credentials/
author: Daniel Koifman (@Koifsec), Nasreddine Bencherchali
date: 2024-10-21
tags:
    - attack.credential-access
    - attack.t1555.003
    - detection.threat-hunting
logsource:
    product: windows
    service: security
    definition: 'Requirements: Audit File System subcategory must be enabled. Additionally, each listed ObjectName must have "List folder/read data" auditing enabled.'
detection:
    selection_eid:
        EventID: 4663
        ObjectType: 'File'
        # Note: This AccessMask requires enhancements. As this access can be combined with other requests. It should include all possible outcomes where READ access and similar are part of it.
        AccessMask: '0x1'
    selection_browser_chromium:
        ObjectName|contains:
            - '\User Data\Default\Login Data'
            - '\User Data\Local State'
            - '\User Data\Default\Network\Cookies'
    selection_browser_firefox:
        FileName|endswith:
            - '\cookies.sqlite'
            - '\places.sqlite'
            - 'release\key3.db'  # Firefox
            - 'release\key4.db'  # Firefox
            - 'release\logins.json' # Firefox
    filter_main_system:
        ProcessName: System
    filter_main_generic:
        # This filter is added to avoid large amount of FP with 3rd party software. You should remove this in favour of specific filter per-application
        ProcessName|startswith:
            - 'C:\Program Files (x86)\'
            - 'C:\Program Files\'
            - 'C:\Windows\system32\'
            - 'C:\Windows\SysWOW64\'
    filter_optional_defender:
        ProcessName|startswith: 'C:\ProgramData\Microsoft\Windows Defender\'
        ProcessName|endswith:
            - '\MpCopyAccelerator.exe'
            - '\MsMpEng.exe'
    condition: selection_eid and 1 of selection_browser_* and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: low

Stages and Predicates

Stage 0: condition

selection_eid and 1 of selection_browser_* and not 1 of filter_main_* and not 1 of filter_optional_*

Stage 1: selection_eid

selection_eid:
    EventID: 4663
    ObjectType: 'File'
    AccessMask: '0x1'

Stage 2: selection_browser_chromium

selection_browser_chromium:
    ObjectName|contains:
        - '\User Data\Default\Login Data'
        - '\User Data\Local State'
        - '\User Data\Default\Network\Cookies'

Stage 3: selection_browser_firefox

selection_browser_firefox:
    FileName|endswith:
        - '\cookies.sqlite'
        - '\places.sqlite'
        - 'release\key3.db'
        - 'release\key4.db'
        - 'release\logins.json'

Stage 4: not filter_main_*

filter_main_system:
    ProcessName: System
filter_main_generic:
    ProcessName|startswith:
        - 'C:\Program Files (x86)\'
        - 'C:\Program Files\'
        - 'C:\Windows\system32\'
        - 'C:\Windows\SysWOW64\'

Stage 5: not filter_optional_defender

filter_optional_defender:
    ProcessName|startswith: 'C:\ProgramData\Microsoft\Windows Defender\'
    ProcessName|endswith:
        - '\MpCopyAccelerator.exe'
        - '\MsMpEng.exe'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
AccessMaskeq
  • 0x1
field:"AccessMask" kind:eq value:"0x1"
FileNameends_with
  • \cookies.sqlite corpus 2 (sigma 2)
  • \places.sqlite corpus 2 (sigma 2)
  • release\key3.db corpus 2 (sigma 2)
  • release\key4.db corpus 2 (sigma 2)
  • release\logins.json corpus 2 (sigma 2)
field:"file_name" kind:ends_with
ObjectNamematch
  • \User Data\Default\Login Data
  • \User Data\Default\Network\Cookies
  • \User Data\Local State
field:"ObjectName" kind:match
ObjectTypeeq
  • File corpus 12 (sigma 8, splunk 4)
field:"ObjectType" kind:eq value:"File"

Exclusions

The rule actively suppresses these predicates.

Add or Remove Computer from DC

#
Status
test
Severity
low
Author
frack113
Source
github.com/SigmaHQ/sigma

Detects the creation or removal of a computer. Can be used to detect attacks such as DCShadow via the creation of a new SPN.

MITRE ATT&CK Coverage

TacticTechniques
Defense Impairment

Telemetry Coverage

Rule Body

title: Add or Remove Computer from DC
id: 20d96d95-5a20-4cf1-a483-f3bda8a7c037
status: test
description: Detects the creation or removal of a computer. Can be used to detect attacks such as DCShadow via the creation of a new SPN.
references:
    - https://github.com/Yamato-Security/EnableWindowsLogSettings/blob/7f6d755d45ac7cc9fc35b0cbf498e6aa4ef19def/ConfiguringSecurityLogAuditPolicies.md
    - https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-10/security/threat-protection/auditing/event-4741
    - https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-10/security/threat-protection/auditing/event-4743
author: frack113
date: 2022-10-14
tags:
    - attack.defense-impairment
    - attack.t1207
logsource:
    service: security
    product: windows
detection:
    selection:
        EventID:
            - 4741
            - 4743
    condition: selection
falsepositives:
    - Unknown
level: low

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    EventID:
        - 4741
        - 4743

Azure DNS Zone Modified or Deleted

#
Status
test
Severity
medium
Author
Austin Songer @austinsonger
Source
github.com/SigmaHQ/sigma

Identifies when DNS zone is modified or deleted.

Known False Positives

  • DNS zone modified and deleted may be performed by a system administrator. Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
  • DNS zone modification from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.

MITRE ATT&CK Coverage

Rule Body

title: Azure DNS Zone Modified or Deleted
id: af6925b0-8826-47f1-9324-337507a0babd
status: test
description: Identifies when DNS zone is modified or deleted.
references:
    - https://learn.microsoft.com/en-us/azure/role-based-access-control/resource-provider-operations#microsoftkubernetes
author: Austin Songer @austinsonger
date: 2021-08-08
modified: 2022-08-23
tags:
    - attack.impact
    - attack.t1565.001
logsource:
    product: azure
    service: activitylogs
detection:
    selection:
        operationName|startswith: 'MICROSOFT.NETWORK/DNSZONES'
        operationName|endswith:
            - '/WRITE'
            - '/DELETE'
    condition: selection
falsepositives:
    - DNS zone modified and deleted may be performed by a system administrator. Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
    - DNS zone modification from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    operationName|startswith: 'MICROSOFT.NETWORK/DNSZONES'
    operationName|endswith:
        - '/WRITE'
        - '/DELETE'

Indicators

These rows show field, operator, and value matches.

Azure Kubernetes RoleBinding/ClusterRoleBinding Modified and Deleted

#
Status
test
Severity
medium
Author
Austin Songer @austinsonger
Source
github.com/SigmaHQ/sigma

Detects the creation or patching of potential malicious RoleBinding/ClusterRoleBinding.

Known False Positives

  • RoleBinding/ClusterRoleBinding being modified and deleted may be performed by a system administrator. Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
  • RoleBinding/ClusterRoleBinding modification from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.

MITRE ATT&CK Coverage

Rule Body

title: Azure Kubernetes RoleBinding/ClusterRoleBinding Modified and Deleted
id: 25cb259b-bbdc-4b87-98b7-90d7c72f8743
status: test
description: Detects the creation or patching of potential malicious RoleBinding/ClusterRoleBinding.
references:
    - https://learn.microsoft.com/en-us/azure/role-based-access-control/resource-provider-operations#microsoftkubernetes
    - https://www.microsoft.com/security/blog/2021/03/23/secure-containerized-environments-with-updated-threat-matrix-for-kubernetes/
    - https://www.microsoft.com/security/blog/2020/04/02/attack-matrix-kubernetes/
    - https://medium.com/mitre-engenuity/att-ck-for-containers-now-available-4c2359654bf1
author: Austin Songer @austinsonger
date: 2021-08-07
modified: 2022-08-23
tags:
    - attack.impact
    - attack.credential-access
    - attack.t1485
    - attack.t1496
    - attack.t1489
logsource:
    product: azure
    service: activitylogs
detection:
    selection:
        operationName:
            - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/CLUSTERROLEBINDINGS/WRITE
            - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/CLUSTERROLEBINDINGS/DELETE
            - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/ROLEBINDINGS/WRITE
            - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/ROLEBINDINGS/DELETE
    condition: selection
falsepositives:
    - RoleBinding/ClusterRoleBinding being modified and deleted may be performed by a system administrator. Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
    - RoleBinding/ClusterRoleBinding modification from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    operationName:
        - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/CLUSTERROLEBINDINGS/WRITE
        - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/CLUSTERROLEBINDINGS/DELETE
        - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/ROLEBINDINGS/WRITE
        - MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/ROLEBINDINGS/DELETE

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
operationNameeq
  • MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/CLUSTERROLEBINDINGS/DELETE
  • MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/CLUSTERROLEBINDINGS/WRITE
  • MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/ROLEBINDINGS/DELETE
  • MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/RBAC.AUTHORIZATION.K8S.IO/ROLEBINDINGS/WRITE
field:"operationName" kind:eq

Cisco Crypto Commands

#
Status
test
Severity
high
Author
Austin Clark
Source
github.com/SigmaHQ/sigma

Show when private keys are being exported from the device, or when new certificates are installed

Known False Positives

  • Not commonly run by administrators. Also whitelist your known good certificates

MITRE ATT&CK Coverage

Rule Body

title: Cisco Crypto Commands
id: 1f978c6a-4415-47fb-aca5-736a44d7ca3d
status: test
description: Show when private keys are being exported from the device, or when new certificates are installed
references:
    - https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/security/a1/sec-a1-cr-book/sec-a1-cr-book_chapter_0111.html
author: Austin Clark
date: 2019-08-12
modified: 2023-01-04
tags:
    - attack.credential-access
    - attack.defense-impairment
    - attack.t1553.004
    - attack.t1552.004
logsource:
    product: cisco
    service: aaa
detection:
    keywords:
        - 'crypto pki export'
        - 'crypto pki import'
        - 'crypto pki trustpoint'
    condition: keywords
falsepositives:
    - Not commonly run by administrators. Also whitelist your known good certificates
level: high

Stages and Predicates

Stage 0: condition

keywords

Stage 1: keywords

keywords:
    - 'crypto pki export'
    - 'crypto pki import'
    - 'crypto pki trustpoint'

Cobalt Strike DNS Beaconing

#
Status
test
Severity
critical
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects suspicious DNS queries known from Cobalt Strike beacons

MITRE ATT&CK Coverage

TacticTechniques
Command & Control

Rule Body

title: Cobalt Strike DNS Beaconing
id: 2975af79-28c4-4d2f-a951-9095f229df29
status: test
description: Detects suspicious DNS queries known from Cobalt Strike beacons
references:
    - https://www.icebrg.io/blog/footprints-of-fin7-tracking-actor-patterns
    - https://www.sekoia.io/en/hunting-and-detecting-cobalt-strike/
author: Florian Roth (Nextron Systems)
date: 2018-05-10
modified: 2022-10-09
tags:
    - attack.command-and-control
    - attack.t1071.004
logsource:
    category: dns
detection:
    selection1:
        query|startswith:
            - 'aaa.stage.'
            - 'post.1'
    selection2:
        query|contains: '.stage.123456.'
    condition: 1 of selection*
falsepositives:
    - Unknown
level: critical

Stages and Predicates

Stage 0: condition

1 of selection*

Stage 1: selection1

selection1:
    query|startswith:
        - 'aaa.stage.'
        - 'post.1'

Stage 2: selection2

selection2:
    query|contains: '.stage.123456.'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
querymatch
  • .stage.123456.
field:"query" kind:match value:".stage.123456."
querystarts_with
  • aaa.stage.
  • post.1
field:"query" kind:starts_with

DEWMODE Webshell Access

#
Status
test
Severity
high
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects access to DEWMODE webshell as described in FIREEYE report

MITRE ATT&CK Coverage

Rule Body

title: DEWMODE Webshell Access
id: fdf96c90-42d5-4406-8a9c-14a2c9a016b5
status: test
description: Detects access to DEWMODE webshell as described in FIREEYE report
references:
    - https://www.mandiant.com/resources/blog/accellion-fta-exploited-for-data-theft-and-extortion
author: Florian Roth (Nextron Systems)
date: 2021-02-22
modified: 2023-01-02
tags:
    - attack.persistence
    - attack.t1505.003
    - detection.emerging-threats
logsource:
    category: webserver
detection:
    selection1:
        cs-uri-query|contains|all:
            - '?dwn='
            - '&fn='
            - '.html?'
    selection2:
        cs-uri-query|contains|all:
            - '&dwn='
            - '?fn='
            - '.html?'
    condition: 1 of selection*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

1 of selection*

Stage 1: selection1

selection1:
    cs-uri-query|contains|all:
        - '?dwn='
        - '&fn='
        - '.html?'

Stage 2: selection2

selection2:
    cs-uri-query|contains|all:
        - '&dwn='
        - '?fn='
        - '.html?'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
cs-uri-querymatch
  • &dwn=
  • &fn=
  • .html?
  • ?dwn=
  • ?fn=
field:"cs-uri-query" kind:match

ESXi Syslog Configuration Change Via ESXCLI

#
Status
test
Severity
medium
Author
Cedric Maurugeon
Source
github.com/SigmaHQ/sigma

Detects changes to the ESXi syslog configuration via "esxcli"

Known False Positives

  • Legitimate administrative activities

MITRE ATT&CK Coverage

Telemetry Coverage

PlatformRecord / event type
LinuxEvent ID 1: Process Create

Rule Body

title: ESXi Syslog Configuration Change Via ESXCLI
id: 38eb1dbb-011f-40b1-a126-cf03a0210563
status: test
description: Detects changes to the ESXi syslog configuration via "esxcli"
references:
    - https://support.solarwinds.com/SuccessCenter/s/article/Configure-ESXi-Syslog-to-LEM?language=en_US
    - https://developer.broadcom.com/xapis/esxcli-command-reference/7.0.0/namespace/esxcli_system.html
author: Cedric Maurugeon
date: 2023-09-04
tags:
    - attack.execution
    - attack.defense-impairment
    - attack.t1685
    - attack.t1690
    - attack.t1059.012
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith: '/esxcli'
        CommandLine|contains|all:
            - 'system'
            - 'syslog'
            - 'config'
        CommandLine|contains: ' set'
    condition: selection
falsepositives:
    - Legitimate administrative activities
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    Image|endswith: '/esxcli'
    CommandLine|contains|all:
        - 'system'
        - 'syslog'
        - 'config'
    CommandLine|contains: ' set'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • set corpus 2 (sigma 2)
  • config corpus 16 (sigma 15, splunk 1)
  • syslog
  • system corpus 8 (sigma 4, splunk 3, elastic 1)
field:"CommandLine" kind:match
Imageends_with
  • /esxcli corpus 9 (sigma 9)
field:"Image" kind:ends_with value:"/esxcli"

Goofy Guineapig Backdoor Potential C2 Communication

#
Status
test
Severity
high
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects potential C2 communication related to Goofy Guineapig backdoor

Known False Positives

  • Unlikely

MITRE ATT&CK Coverage

TacticTechniques
Command & ControlNo specific technique

Rule Body

title: Goofy Guineapig Backdoor Potential C2 Communication
id: 4f573bb6-701a-4b8d-91db-87ae106e9a61
status: test
description: Detects potential C2 communication related to Goofy Guineapig backdoor
references:
    - https://www.ncsc.gov.uk/static-assets/documents/malware-analysis-reports/goofy-guineapig/NCSC-MAR-Goofy-Guineapig.pdf
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-05-14
tags:
    - attack.command-and-control
    - detection.emerging-threats
logsource:
    category: proxy
detection:
    selection:
        c-useragent: 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36'
        cs-host: 'static.tcplog.com'
    condition: selection
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    c-useragent: 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36'
    cs-host: 'static.tcplog.com'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
c-useragenteq
  • Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36
field:"c-useragent" kind:eq value:"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36"
cs-hosteq
  • static.tcplog.com
field:"cs-host" kind:eq value:"static.tcplog.com"

HackTool - HandleKatz LSASS Dumper Execution

#
Status
test
Severity
high
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the use of HandleKatz, a tool that demonstrates the usage of cloned handles to Lsass in order to create an obfuscated memory dump of the same

MITRE ATT&CK Coverage

TacticTechniques
Credential Access

Telemetry Coverage

ProviderRecord / event type
SysmonEvent ID 1: Process creation

Rule Body

title: HackTool - HandleKatz LSASS Dumper Execution
id: ca621ba5-54ab-4035-9942-d378e6fcde3c
status: test
description: Detects the use of HandleKatz, a tool that demonstrates the usage of cloned handles to Lsass in order to create an obfuscated memory dump of the same
references:
    - https://github.com/codewhitesec/HandleKatz
author: Florian Roth (Nextron Systems)
date: 2022-08-18
modified: 2024-11-23
tags:
    - attack.credential-access
    - attack.t1003.001
logsource:
    category: process_creation
    product: windows
detection:
    selection_loader_img:
        Image|endswith: '\loader.exe'
        CommandLine|contains: '--pid:'
    selection_loader_imphash:
        Hashes|contains:
            - 'IMPHASH=38D9E015591BBFD4929E0D0F47FA0055'
            - 'IMPHASH=0E2216679CA6E1094D63322E3412D650'
    selection_flags:
        CommandLine|contains|all:
            - '--pid:'
            - '--outfile:'
        CommandLine|contains:
            - '.dmp'
            - 'lsass'
            - '.obf'
            - 'dump'
    condition: 1 of selection_*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

1 of selection_*

Stage 1: selection_loader_img

selection_loader_img:
    Image|endswith: '\loader.exe'
    CommandLine|contains: '--pid:'

Stage 2: selection_loader_imphash

selection_loader_imphash:
    Hashes|contains:
        - 'IMPHASH=38D9E015591BBFD4929E0D0F47FA0055'
        - 'IMPHASH=0E2216679CA6E1094D63322E3412D650'

Stage 3: selection_flags

selection_flags:
    CommandLine|contains|all:
        - '--pid:'
        - '--outfile:'
    CommandLine|contains:
        - '.dmp'
        - 'lsass'
        - '.obf'
        - 'dump'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • --outfile:
  • --pid:
  • .dmp corpus 8 (sigma 8)
  • .obf
  • dump
  • lsass corpus 7 (sigma 6, elastic 1)
field:"CommandLine" kind:match
Hashesmatch
  • IMPHASH=0E2216679CA6E1094D63322E3412D650 corpus 3 (sigma 3)
  • IMPHASH=38D9E015591BBFD4929E0D0F47FA0055 corpus 3 (sigma 3)
field:"Hashes" kind:match
Imageends_with
  • \loader.exe
field:"Image" kind:ends_with value:"\loader.exe"

HackTool - SharpDPAPI Execution

#
Status
test
Severity
high
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the execution of the SharpDPAPI tool based on CommandLine flags and PE metadata. SharpDPAPI is a C# port of some DPAPI functionality from the Mimikatz project.

MITRE ATT&CK Coverage

Telemetry Coverage

ProviderRecord / event type
SysmonEvent ID 1: Process creation

Rule Body

title: HackTool - SharpDPAPI Execution
id: c7d33b50-f690-4b51-8cfb-0fb912a31e57
status: test
description: |
    Detects the execution of the SharpDPAPI tool based on CommandLine flags and PE metadata.
    SharpDPAPI is a C# port of some DPAPI functionality from the Mimikatz project.
references:
    - https://github.com/GhostPack/SharpDPAPI
author: Nasreddine Bencherchali (Nextron Systems)
date: 2024-06-26
tags:
    - attack.privilege-escalation
    - attack.stealth
    - attack.t1134.001
    - attack.t1134.003
logsource:
    product: windows
    category: process_creation
detection:
    selection_img:
        - Image|endswith: '\SharpDPAPI.exe'
        - OriginalFileName: 'SharpDPAPI.exe'
    selection_other_cli:
        CommandLine|contains:
            - ' backupkey '
            - ' blob '
            - ' certificates '
            - ' credentials '
            - ' keepass '
            - ' masterkeys '
            - ' rdg '
            - ' vaults '
    selection_other_options_guid:
        CommandLine|contains|all:
            - ' {'
            - '}:'
    selection_other_options_flags:
        CommandLine|contains:
            - ' /file:'
            - ' /machine'
            - ' /mkfile:'
            - ' /password:'
            - ' /pvk:'
            - ' /server:'
            - ' /target:'
            - ' /unprotect'
    condition: selection_img or (selection_other_cli and 1 of selection_other_options_*)
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection_img or (selection_other_cli and 1 of selection_other_options_*)

Stage 1: selection_img

selection_img:
    - Image|endswith: '\SharpDPAPI.exe'
    - OriginalFileName: 'SharpDPAPI.exe'

Stage 2: selection_other_cli

selection_other_cli:
    CommandLine|contains:
        - ' backupkey '
        - ' blob '
        - ' certificates '
        - ' credentials '
        - ' keepass '
        - ' masterkeys '
        - ' rdg '
        - ' vaults '

Stage 3: selection_other_options_guid

selection_other_options_guid:
    CommandLine|contains|all:
        - ' {'
        - '}:'

Stage 4: selection_other_options_flags

selection_other_options_flags:
    CommandLine|contains:
        - ' /file:'
        - ' /machine'
        - ' /mkfile:'
        - ' /password:'
        - ' /pvk:'
        - ' /server:'
        - ' /target:'
        - ' /unprotect'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • /file:
  • /machine
  • /mkfile:
  • /password:
  • /pvk:
  • /server:
  • /target:
  • /unprotect
  • backupkey
  • blob
  • certificates
  • credentials
  • keepass
  • masterkeys
  • rdg
  • vaults
  • {
  • }:
field:"CommandLine" kind:match
Imageends_with
  • \SharpDPAPI.exe
field:"Image" kind:ends_with value:"\SharpDPAPI.exe"
OriginalFileNameeq
  • SharpDPAPI.exe
field:"OriginalFileName" kind:eq value:"SharpDPAPI.exe"

Kubernetes Secrets Enumeration

#
Status
test
Severity
low
Author
Leo Tsaousis (@laripping)
Source
github.com/SigmaHQ/sigma

Detects enumeration of Kubernetes secrets.

Known False Positives

  • The Kubernetes dashboard occasionally accesses the kubernetes-dashboard-key-holder secret

MITRE ATT&CK Coverage

TacticTechniques
Credential Access

Telemetry Coverage

PlatformRecord / event type
Kuberneteslist-secrets: list secrets

Rules Detecting the Same Action

These rules filter on the same operation.

Rule Body

title: Kubernetes Secrets Enumeration
id: eeb3e9e1-b685-44e4-9232-6bb701f925b5
related:
    - id: 7ee0b4aa-d8d4-4088-b661-20efdf41a04c
      type: derived
status: test
description: Detects enumeration of Kubernetes secrets.
references:
    - https://microsoft.github.io/Threat-Matrix-for-Kubernetes/techniques/List%20K8S%20secrets/
author: Leo Tsaousis (@laripping)
date: 2024-03-26
tags:
    - attack.t1552.007
    - attack.credential-access
logsource:
    category: application
    product: kubernetes
    service: audit
detection:
    selection:
        verb: 'list'
        objectRef.resource: 'secrets'
    condition: selection
falsepositives:
    - The Kubernetes dashboard occasionally accesses the kubernetes-dashboard-key-holder secret
level: low

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    verb: 'list'
    objectRef.resource: 'secrets'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
objectRef.resourceeq
  • secrets corpus 6 (splunk 4, sigma 2)
field:"objectRef.resource" kind:eq value:"secrets"
verbeq
  • list corpus 2 (sigma 1, splunk 1)
field:"verb" kind:eq value:"list"

Linux Webshell Indicators

#
Status
test
Severity
high
Author
Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects suspicious sub processes of web server processes

Known False Positives

  • Web applications that invoke Linux command line tools

MITRE ATT&CK Coverage

Telemetry Coverage

PlatformRecord / event type
LinuxEvent ID 1: Process Create

Rule Body

title: Linux Webshell Indicators
id: 818f7b24-0fba-4c49-a073-8b755573b9c7
status: test
description: Detects suspicious sub processes of web server processes
references:
    - https://www.acunetix.com/blog/articles/web-shells-101-using-php-introduction-web-shells-part-2/
    - https://media.defense.gov/2020/Jun/09/2002313081/-1/-1/0/CSI-DETECT-AND-PREVENT-WEB-SHELL-MALWARE-20200422.PDF
author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2021-10-15
modified: 2026-08-19
tags:
    - attack.persistence
    - attack.t1505.003
logsource:
    product: linux
    category: process_creation
detection:
    selection_parent_general:
        ParentImage|endswith:
            - '/httpd'
            - '/lighttpd'
            - '/nginx'
            - '/apache2'
            - '/node'
            - '/caddy'
    selection_parent_tomcat:
        ParentCommandLine|contains|all:
            - '/bin/java'
            - 'tomcat'
    selection_parent_websphere:  # ? just guessing
        ParentCommandLine|contains|all:
            - '/bin/java'
            - 'websphere'
    selection_child_processes:
        Image|endswith:
            - '/whoami'
            - '/ifconfig'
            - '/ip'
            - '/bin/uname'
            - '/bin/cat'
            - '/bin/crontab'
            - '/hostname'
            - '/iptables'
            - '/netstat'
            - '/pwd'
            - '/route'
    filter_optional_ip_neigh:
        ParentImage|endswith: '/node'
        CommandLine|contains: 'ip neigh show'
    condition: 1 of selection_parent_* and selection_child_processes and not 1 of filter_optional_*
falsepositives:
    - Web applications that invoke Linux command line tools
level: high

Stages and Predicates

Stage 0: condition

1 of selection_parent_* and selection_child_processes and not 1 of filter_optional_*

Stage 1: selection_parent_general

selection_parent_general:
    ParentImage|endswith:
        - '/httpd'
        - '/lighttpd'
        - '/nginx'
        - '/apache2'
        - '/node'
        - '/caddy'

Stage 2: selection_parent_tomcat

selection_parent_tomcat:
    ParentCommandLine|contains|all:
        - '/bin/java'
        - 'tomcat'

Stage 3: selection_parent_websphere

selection_parent_websphere:
    ParentCommandLine|contains|all:
        - '/bin/java'
        - 'websphere'

Stage 4: selection_child_processes

selection_child_processes:
    Image|endswith:
        - '/whoami'
        - '/ifconfig'
        - '/ip'
        - '/bin/uname'
        - '/bin/cat'
        - '/bin/crontab'
        - '/hostname'
        - '/iptables'
        - '/netstat'
        - '/pwd'
        - '/route'

Stage 5: not filter_optional_ip_neigh

filter_optional_ip_neigh:
    ParentImage|endswith: '/node'
    CommandLine|contains: 'ip neigh show'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Imageends_with
  • /bin/cat
  • /bin/crontab
  • /bin/uname
  • /hostname corpus 2 (sigma 2)
  • /ifconfig corpus 4 (sigma 4)
  • /ip corpus 3 (sigma 3)
  • /iptables corpus 3 (sigma 3)
  • /netstat corpus 6 (sigma 6)
  • /pwd
  • /route corpus 2 (sigma 2)
  • /whoami corpus 2 (sigma 2)
field:"Image" kind:ends_with
ParentCommandLinematch
  • /bin/java
  • tomcat corpus 2 (sigma 2)
  • websphere
field:"ParentCommandLine" kind:match
ParentImageends_with
  • /apache2
  • /caddy
  • /httpd
  • /lighttpd
  • /nginx
  • /node corpus 5 (sigma 5)
field:"ParentImage" kind:ends_with

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
CommandLinematchip neigh showexcludes:CommandLine field:"CommandLine" value:"ip neigh show"
ParentImageends_with/nodeexcludes:ParentImage field:"ParentImage" value:"/node"

Narrator's Feedback-Hub Persistence

#
Status
test
Severity
high
Author
Dmitriy Lifanov, oscd.community
Source
github.com/SigmaHQ/sigma

Detects abusing Windows 10 Narrator's Feedback-Hub

MITRE ATT&CK Coverage

Telemetry Coverage

Rule Body

title: Narrator's Feedback-Hub Persistence
id: f663a6d9-9d1b-49b8-b2b1-0637914d199a
status: test
description: Detects abusing Windows 10 Narrator's Feedback-Hub
references:
    - https://giuliocomi.blogspot.com/2019/10/abusing-windows-10-narrators-feedback.html
author: Dmitriy Lifanov, oscd.community
date: 2019-10-25
modified: 2022-03-26
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1547.001
logsource:
    category: registry_event
    product: windows
detection:
    selection1:
        EventType: DeleteValue
        TargetObject|endswith: '\AppXypsaf9f1qserqevf0sws76dx4k9a5206\Shell\open\command\DelegateExecute'
    selection2:
        TargetObject|endswith: '\AppXypsaf9f1qserqevf0sws76dx4k9a5206\Shell\open\command\(Default)'
    # Add the payload in the (Default)
    condition: 1 of selection*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

1 of selection*

Stage 1: selection1

selection1:
    EventType: DeleteValue
    TargetObject|endswith: '\AppXypsaf9f1qserqevf0sws76dx4k9a5206\Shell\open\command\DelegateExecute'

Stage 2: selection2

selection2:
    TargetObject|endswith: '\AppXypsaf9f1qserqevf0sws76dx4k9a5206\Shell\open\command\(Default)'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
EventTypeeq
  • DeleteValue corpus 5 (sigma 4, splunk 1)
field:"EventType" kind:eq value:"DeleteValue"
TargetObjectends_with
  • \AppXypsaf9f1qserqevf0sws76dx4k9a5206\Shell\open\command\(Default)
  • \AppXypsaf9f1qserqevf0sws76dx4k9a5206\Shell\open\command\DelegateExecute
field:"TargetObject" kind:ends_with

Non-Standard Nsswitch.Conf Creation - Potential CVE-2025-32463 Exploitation

#
Status
experimental
Severity
high
Author
Swachchhanda Shrawn Poudel (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the creation of nsswitch.conf files in non-standard directories, which may indicate exploitation of CVE-2025-32463. This vulnerability requires an attacker to create a nsswitch.conf in a directory that will be used during sudo chroot operations. When sudo executes, it loads malicious shared libraries from user-controlled locations within the chroot environment, potentially leading to arbitrary code execution and privilege escalation.

Known False Positives

  • Backup locations

MITRE ATT&CK Coverage

TacticTechniques
Privilege Escalation

Telemetry Coverage

PlatformRecord / event type
LinuxEvent ID 11: File created

Rule Body

title: Non-Standard Nsswitch.Conf Creation - Potential CVE-2025-32463 Exploitation
id: 10ac0730-c24e-4f4c-81f8-b13a1ac95a1d
status: experimental
description: |
    Detects the creation of nsswitch.conf files in non-standard directories, which may indicate exploitation of CVE-2025-32463.
    This vulnerability requires an attacker to create a nsswitch.conf in a directory that will be used during sudo chroot operations.
    When sudo executes, it loads malicious shared libraries from user-controlled locations within the chroot environment,
    potentially leading to arbitrary code execution and privilege escalation.
references:
    - https://github.com/kh4sh3i/CVE-2025-32463/blob/81bb430f84fa2089224733c3ed4bfa434c197ad4/exploit.sh
author: Swachchhanda Shrawn Poudel (Nextron Systems)
date: 2025-10-02
modified: 2026-03-31
tags:
    - attack.privilege-escalation
    - attack.t1068
    - cve.2025-32463
    - detection.emerging-threats
logsource:
    category: file_event
    product: linux
detection:
    selection:
        TargetFilename|endswith: '/etc/nsswitch.conf'
    filter_main_legitimate_path:
        TargetFilename:
            - '/etc/nsswitch.conf'
            - '/usr/share/factory/etc/nsswitch.conf'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Backup locations
level: high

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    TargetFilename|endswith: '/etc/nsswitch.conf'

Stage 2: not filter_main_legitimate_path

filter_main_legitimate_path:
    TargetFilename:
        - '/etc/nsswitch.conf'
        - '/usr/share/factory/etc/nsswitch.conf'

Indicators

These rows show field, operator, and value matches.

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
TargetFilenameeq/etc/nsswitch.confexcludes:TargetFilename field:"TargetFilename" value:"/etc/nsswitch.conf"
TargetFilenameeq/usr/share/factory/etc/nsswitch.confexcludes:TargetFilename field:"TargetFilename" value:"/usr/share/factory/etc/nsswitch.conf"

Potential Malicious Usage of CloudTrail System Manager

#
Status
test
Severity
high
Author
jamesc-grafana
Source
github.com/SigmaHQ/sigma

Detect when System Manager successfully executes commands against an instance.

Known False Positives

  • There are legitimate uses of SSM to send commands to EC2 instances
  • Legitimate users may have to use SSM to perform actions against machines in the Cloud to update or maintain them

MITRE ATT&CK Coverage

TacticTechniques
Initial Access

Telemetry Coverage

Rules Detecting the Same Action

These rules filter on the same operation.

Rule Body

title: Potential Malicious Usage of CloudTrail System Manager
id: 38e7f511-3f74-41d4-836e-f57dfa18eead
status: test
description: |
    Detect when System Manager successfully executes commands against an instance.
references:
    - https://github.com/elastic/detection-rules/blob/v8.6.0/rules/integrations/aws/initial_access_via_system_manager.toml
author: jamesc-grafana
date: 2024-07-11
modified: 2025-12-08
tags:
    - attack.privilege-escalation
    - attack.initial-access
    - attack.t1566
    - attack.t1566.002
logsource:
    product: aws
    service: cloudtrail
detection:
    selection_event:
        eventName: 'SendCommand'
        eventSource: 'ssm.amazonaws.com'
    selection_status_success:
        errorCode: 'Success'
    selection_status_null:
        errorCode: null
    condition: selection_event and 1 of selection_status_*
falsepositives:
    - There are legitimate uses of SSM to send commands to EC2 instances
    - Legitimate users may have to use SSM to perform actions against machines in the Cloud to update or maintain them
level: high

Stages and Predicates

Stage 0: condition

selection_event and 1 of selection_status_*

Stage 1: selection_event

selection_event:
    eventName: 'SendCommand'
    eventSource: 'ssm.amazonaws.com'

Stage 2: selection_status_success

selection_status_success:
    errorCode: 'Success'

Stage 3: selection_status_null

selection_status_null:
    errorCode: null

Indicators

These rows show field, operator, and value matches.

Potential Persistence Via PowerShell User Profile Using Add-Content

#
Status
test
Severity
medium
Author
frack113, Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects calls to "Add-Content" cmdlet in order to modify the content of the user profile and potentially adding suspicious commands for persistence

Known False Positives

  • Legitimate administration and tuning scripts that aim to add functionality to a user PowerShell session

MITRE ATT&CK Coverage

Telemetry Coverage

Rule Body

title: Potential Persistence Via PowerShell User Profile Using Add-Content
id: 05b3e303-faf0-4f4a-9b30-46cc13e69152
status: test
description: Detects calls to "Add-Content" cmdlet in order to modify the content of the user profile and potentially adding suspicious commands for persistence
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.013/T1546.013.md
author: frack113, Nasreddine Bencherchali (Nextron Systems)
date: 2021-08-18
modified: 2023-05-04
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.t1546.013
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection_add:
        ScriptBlockText|contains: 'Add-Content $profile'
    selection_options:
        ScriptBlockText|contains:
            # Note: You can add more suspicious values
            - '-Value "IEX '
            - '-Value "Invoke-Expression'
            - '-Value "Invoke-WebRequest'
            - '-Value "Start-Process'
            - "-Value 'IEX "
            - "-Value 'Invoke-Expression"
            - "-Value 'Invoke-WebRequest"
            - "-Value 'Start-Process"
    condition: all of selection_*
falsepositives:
    - Legitimate administration and tuning scripts that aim to add functionality to a user PowerShell session
level: medium

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_add

selection_add:
    ScriptBlockText|contains: 'Add-Content $profile'

Stage 2: selection_options

selection_options:
    ScriptBlockText|contains:
        - '-Value "IEX '
        - '-Value "Invoke-Expression'
        - '-Value "Invoke-WebRequest'
        - '-Value "Start-Process'
        - "-Value 'IEX "
        - "-Value 'Invoke-Expression"
        - "-Value 'Invoke-WebRequest"
        - "-Value 'Start-Process"

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
ScriptBlockTextmatch
  • -Value "IEX
  • -Value "Invoke-Expression
  • -Value "Invoke-WebRequest
  • -Value "Start-Process
  • -Value 'IEX
  • -Value 'Invoke-Expression
  • -Value 'Invoke-WebRequest
  • -Value 'Start-Process
  • Add-Content $profile
field:"ScriptBlockText" kind:match

Potential Provlaunch.EXE Binary Proxy Execution Abuse

#
Status
test
Severity
medium
Author
Nasreddine Bencherchali (Nextron Systems), Swachchhanda Shrawan Poudel
Source
github.com/SigmaHQ/sigma

Detects child processes of "provlaunch.exe" which might indicate potential abuse to proxy execution.

MITRE ATT&CK Coverage

Telemetry Coverage

Rule Body

title: Potential Provlaunch.EXE Binary Proxy Execution Abuse
id: 7f5d1c9a-3e83-48df-95a7-2b98aae6c13c
related:
    - id: f9999590-1f94-4a34-a91e-951e47bedefd # CLI Abuse
      type: similar
    - id: 2a4b3e61-9d22-4e4a-b60f-6e8f0cde6f25 # CLI Registry
      type: similar
    - id: 7021255e-5db3-4946-a8b9-0ba7a4644a69 # Registry
      type: similar
status: test
description: Detects child processes of "provlaunch.exe" which might indicate potential abuse to proxy execution.
references:
    - https://lolbas-project.github.io/lolbas/Binaries/Provlaunch/
    - https://twitter.com/0gtweet/status/1674399582162153472
author: Nasreddine Bencherchali (Nextron Systems), Swachchhanda Shrawan Poudel
date: 2023-08-08
tags:
    - attack.stealth
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\provlaunch.exe'
    filter_main_covered_children:
        # Note: this filter is here to avoid duplicate alerting by f9999590-1f94-4a34-a91e-951e47bedefd
        - Image|endswith:
              - '\calc.exe'
              - '\cmd.exe'
              - '\cscript.exe'
              - '\mshta.exe'
              - '\notepad.exe'
              - '\powershell.exe'
              - '\pwsh.exe'
              - '\regsvr32.exe'
              - '\rundll32.exe'
              - '\wscript.exe'
        - Image|contains:
              - ':\PerfLogs\'
              - ':\Temp\'
              - ':\Users\Public\'
              - '\AppData\Temp\'
              - '\Windows\System32\Tasks\'
              - '\Windows\Tasks\'
              - '\Windows\Temp\'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    ParentImage|endswith: '\provlaunch.exe'

Stage 2: not filter_main_covered_children

filter_main_covered_children:
    - Image|endswith:
          - '\calc.exe'
          - '\cmd.exe'
          - '\cscript.exe'
          - '\mshta.exe'
          - '\notepad.exe'
          - '\powershell.exe'
          - '\pwsh.exe'
          - '\regsvr32.exe'
          - '\rundll32.exe'
          - '\wscript.exe'
    - Image|contains:
          - ':\PerfLogs\'
          - ':\Temp\'
          - ':\Users\Public\'
          - '\AppData\Temp\'
          - '\Windows\System32\Tasks\'
          - '\Windows\Tasks\'
          - '\Windows\Temp\'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
ParentImageends_with
  • \provlaunch.exe corpus 2 (sigma 2)
field:"ParentImage" kind:ends_with value:"\provlaunch.exe"

Exclusions

The rule actively suppresses these predicates.

Sensitive File Dump Via Wbadmin.EXE

#
Status
test
Severity
high
Author
Nasreddine Bencherchali (Nextron Systems), frack113
Source
github.com/SigmaHQ/sigma

Detects the dump of highly sensitive files such as "NTDS.DIT" and "SECURITY" hive. Attackers can leverage the "wbadmin" utility in order to dump sensitive files that might contain credential or sensitive information.

Known False Positives

  • Legitimate backup operation by authorized administrators. Matches must be investigated and allowed on a case by case basis.

MITRE ATT&CK Coverage

TacticTechniques
Credential Access

Telemetry Coverage

ProviderRecord / event type
SysmonEvent ID 1: Process creation

Rule Body

title: Sensitive File Dump Via Wbadmin.EXE
id: 8b93a509-1cb8-42e1-97aa-ee24224cdc15
status: test
description: |
    Detects the dump of highly sensitive files such as "NTDS.DIT" and "SECURITY" hive.
    Attackers can leverage the "wbadmin" utility in order to dump sensitive files that might contain credential or sensitive information.
references:
    - https://github.com/LOLBAS-Project/LOLBAS/blob/2cc01b01132b5c304027a658c698ae09dd6a92bf/yml/OSBinaries/Wbadmin.yml
    - https://lolbas-project.github.io/lolbas/Binaries/Wbadmin/
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/wbadmin-start-recovery
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/wbadmin-start-backup
author: Nasreddine Bencherchali (Nextron Systems), frack113
date: 2024-05-10
tags:
    - attack.credential-access
    - attack.t1003.003
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\wbadmin.exe'
        - OriginalFileName: 'WBADMIN.EXE'
    selection_backup:
        CommandLine|contains:
            - 'start'
            - 'backup'
    selection_path:
        CommandLine|contains:
            - '\config\SAM'
            - '\config\SECURITY'
            - '\config\SYSTEM'
            - '\Windows\NTDS\NTDS.dit'
    condition: all of selection_*
falsepositives:
    - Legitimate backup operation by authorized administrators. Matches must be investigated and allowed on a case by case basis.
level: high

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_img

selection_img:
    - Image|endswith: '\wbadmin.exe'
    - OriginalFileName: 'WBADMIN.EXE'

Stage 2: selection_backup

selection_backup:
    CommandLine|contains:
        - 'start'
        - 'backup'

Stage 3: selection_path

selection_path:
    CommandLine|contains:
        - '\config\SAM'
        - '\config\SECURITY'
        - '\config\SYSTEM'
        - '\Windows\NTDS\NTDS.dit'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • \Windows\NTDS\NTDS.dit corpus 5 (sigma 5)
  • \config\SAM corpus 4 (sigma 4)
  • \config\SECURITY corpus 4 (sigma 4)
  • \config\SYSTEM corpus 3 (sigma 3)
  • backup corpus 6 (sigma 5, splunk 1)
  • start corpus 13 (sigma 11, splunk 2)
field:"CommandLine" kind:match
Imageends_with
  • \wbadmin.exe corpus 7 (sigma 7)
field:"Image" kind:ends_with value:"\wbadmin.exe"
OriginalFileNameeq
  • WBADMIN.EXE corpus 16 (elastic 8, sigma 6, splunk 2)
field:"OriginalFileName" kind:eq value:"WBADMIN.EXE"

Shai-Hulud Malicious Bun Execution - Linux

#
Status
experimental
Severity
high
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the execution of bun_environment.js via the Bun runtime, a behavior associated with the Shai-Hulud "Second Coming" NPM supply chain attack. The malware uses a setup_bun.js script to install the Bun runtime if not present, and then executes the malicious bun_environment.js payload.

Known False Positives

  • Legitimate but uncommon use of files named `bun_environment.js` could trigger this rule.

MITRE ATT&CK Coverage

Telemetry Coverage

PlatformRecord / event type
LinuxEvent ID 1: Process Create

Rule Body

title: Shai-Hulud Malicious Bun Execution - Linux
id: eb827bbd-670a-4d58-8446-c464d8ac2323
related:
    - id: 5299fadf-f228-4526-8274-251db1960be9
      type: similar
status: experimental
description: |
    Detects the execution of `bun_environment.js` via the Bun runtime, a behavior associated with the Shai-Hulud "Second Coming" NPM supply chain attack.
    The malware uses a `setup_bun.js` script to install the Bun runtime if not present, and then executes the malicious `bun_environment.js` payload.
references:
    - https://www.aikido.dev/blog/shai-hulud-strikes-again-hitting-zapier-ensdomains
    - https://www.wiz.io/blog/shai-hulud-2-0-ongoing-supply-chain-attack
    - https://github.com/asyncapi/cli/blob/2efa4dff59bc3d3cecdf897ccf178f99b115d63d/setup_bun.js
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-11-25
tags:
    - attack.t1195.002
    - attack.t1203
    - attack.execution
    - attack.initial-access
    - detection.emerging-threats
logsource:
    category: process_creation
    product: linux
detection:
    selection_parent:
        ParentImage|endswith: '/node'
    selection_child_bun:
        Image|endswith: '/bun'
        CommandLine|contains:
            - 'bun_environment.js'
            - 'https://github.com/actions/runner/releases/download/v2.330.0'
    selection_child_setup_curl:
        CommandLine|contains|all:
            - 'curl '
            - '-fsSL'
            - 'https://bun.sh/install'
            - 'bash'
    selection_child_path_reload:
        CommandLine|contains|all:
            - 'bash -c "source '
            - '&& echo'
    condition: selection_parent and 1 of selection_child_*
falsepositives:
    - Legitimate but uncommon use of files named `bun_environment.js` could trigger this rule.
level: high

Stages and Predicates

Stage 0: condition

selection_parent and 1 of selection_child_*

Stage 1: selection_parent

selection_parent:
    ParentImage|endswith: '/node'

Stage 2: selection_child_bun

selection_child_bun:
    Image|endswith: '/bun'
    CommandLine|contains:
        - 'bun_environment.js'
        - 'https://github.com/actions/runner/releases/download/v2.330.0'

Stage 3: selection_child_setup_curl

selection_child_setup_curl:
    CommandLine|contains|all:
        - 'curl '
        - '-fsSL'
        - 'https://bun.sh/install'
        - 'bash'

Stage 4: selection_child_path_reload

selection_child_path_reload:
    CommandLine|contains|all:
        - 'bash -c "source '
        - '&& echo'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • && echo
  • -fsSL
  • bash corpus 5 (sigma 5)
  • bash -c "source
  • bun_environment.js corpus 2 (sigma 2)
  • curl corpus 11 (sigma 11)
  • https://bun.sh/install
  • https://github.com/actions/runner/releases/download/v2.330.0 corpus 2 (sigma 2)
field:"CommandLine" kind:match
Imageends_with
  • /bun corpus 2 (sigma 2)
field:"Image" kind:ends_with value:"/bun"
ParentImageends_with
  • /node corpus 5 (sigma 5)
field:"ParentImage" kind:ends_with value:"/node"

SQL Server Dedicated Admin Connection (DAC) mode activated (native)

#
Status
experimental
Severity
high
Author
mdecrevoisier
Source
github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker enabled the DAC mode in order to bypass access controls, logon triggers, perform brute force attacks or run unauthorized queries.

Known False Positives

  • Admin attempting to debug or recover a SQL Server

MITRE ATT&CK Coverage

Telemetry Coverage

ProviderRecord / event type
MSSQLSERVEREvent ID 15457

Rule Body

title: SQL Server Dedicated Admin Connection (DAC) mode activated (native)
description: Detects scenarios where an attacker enabled the DAC mode in order to bypass access controls, logon triggers, perform brute force attacks or run unauthorized queries.
references:
- https://josephpierini.blogspot.com/2012/07/microsoft-sql-dedicated-admin.html
- https://www.sqlshack.com/sql-server-dedicated-admin-connection-dac-how-to-enable-connect-and-use/
- https://www.mssqltips.com/sqlservertip/1801/enable-sql-server-dedicated-administrator-connection/
- https://docs.microsoft.com/en-us/sql/relational-databases/errors-events/database-engine-events-and-errors?view=sql-server-ver16
tags:
- attack.persistence
- attack.t1505.001
author: mdecrevoisier
status: experimental
logsource:
  product: mssql
  service: application
detection:
  selection:
    EventID: 15457
    EventData|contains: '<Data>remote admin connections</Data><Data>0</Data><Data>1</Data>' # 0 is for previous status and 1 for new status
  condition: selection
falsepositives:
- Admin attempting to debug or recover a SQL Server
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  EventID: 15457
  EventData|contains: '<Data>remote admin connections</Data><Data>0</Data><Data>1</Data>'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
EventDatamatch
  • <Data>remote admin connections</Data><Data>0</Data><Data>1</Data>
field:"EventData" kind:match value:"<Data>remote admin connections</Data><Data>0</Data><Data>1</Data>"

Suspicious File Write to SharePoint Layouts Directory

#
Status
experimental
Severity
high
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects suspicious file writes to SharePoint layouts directory which could indicate webshell activity or post-exploitation. This behavior has been observed in the exploitation of SharePoint vulnerabilities such as CVE-2025-49704, CVE-2025-49706 or CVE-2025-53770.

MITRE ATT&CK Coverage

Telemetry Coverage

ProviderRecord / event type
SysmonEvent ID 11: FileCreate

Rule Body

title: Suspicious File Write to SharePoint Layouts Directory
id: 1f0489be-b496-4ddf-b3a9-5900f2044e9c
status: experimental
description: |
    Detects suspicious file writes to SharePoint layouts directory which could indicate webshell activity or post-exploitation.
    This behavior has been observed in the exploitation of SharePoint vulnerabilities such as CVE-2025-49704, CVE-2025-49706 or CVE-2025-53770.
references:
    - https://unit42.paloaltonetworks.com/microsoft-sharepoint-cve-2025-49704-cve-2025-49706-cve-2025-53770/
    - https://www.microsoft.com/en-us/security/blog/2025/07/22/disrupting-active-exploitation-of-on-premises-sharepoint-vulnerabilities/
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-07-24
tags:
    - attack.initial-access
    - attack.t1190
    - attack.persistence
    - attack.t1505.003
logsource:
    product: windows
    category: file_event
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell_ise.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\w3wp.exe'
        TargetFilename|startswith:
            - 'C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\'
            - 'C:\Program Files (x86)\Common Files\Microsoft Shared\Web Server Extensions\'
        TargetFilename|contains:
            - '\15\TEMPLATE\LAYOUTS\'
            - '\16\TEMPLATE\LAYOUTS\'
        TargetFilename|endswith:
            - '.asax'
            - '.ascx'
            - '.ashx'
            - '.asmx'
            - '.asp'
            - '.aspx'
            - '.bat'
            - '.cmd'
            - '.cer'
            - '.config'
            - '.hta'
            - '.js'
            - '.jsp'
            - '.jspx'
            - '.php'
            - '.ps1'
            - '.vbs'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    Image|endswith:
        - '\cmd.exe'
        - '\powershell_ise.exe'
        - '\powershell.exe'
        - '\pwsh.exe'
        - '\w3wp.exe'
    TargetFilename|startswith:
        - 'C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\'
        - 'C:\Program Files (x86)\Common Files\Microsoft Shared\Web Server Extensions\'
    TargetFilename|contains:
        - '\15\TEMPLATE\LAYOUTS\'
        - '\16\TEMPLATE\LAYOUTS\'
    TargetFilename|endswith:
        - '.asax'
        - '.ascx'
        - '.ashx'
        - '.asmx'
        - '.asp'
        - '.aspx'
        - '.bat'
        - '.cmd'
        - '.cer'
        - '.config'
        - '.hta'
        - '.js'
        - '.jsp'
        - '.jspx'
        - '.php'
        - '.ps1'
        - '.vbs'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Imageends_with
  • \cmd.exe corpus 132 (sigma 130, splunk 2)
  • \powershell.exe corpus 181 (sigma 180, splunk 1)
  • \powershell_ise.exe corpus 41 (sigma 41)
  • \pwsh.exe corpus 166 (sigma 166)
  • \w3wp.exe corpus 5 (sigma 5)
field:"Image" kind:ends_with
TargetFilenameends_with
  • .asax
  • .ascx
  • .ashx corpus 3 (sigma 3)
  • .asmx
  • .asp corpus 4 (sigma 4)
  • .aspx corpus 5 (sigma 5)
  • .bat corpus 17 (sigma 17)
  • .cer corpus 2 (sigma 2)
  • .cmd corpus 8 (sigma 8)
  • .config
  • .hta corpus 14 (sigma 14)
  • .js corpus 10 (sigma 10)
  • .jsp corpus 5 (sigma 4, splunk 1)
  • .jspx
  • .php
  • .ps1 corpus 17 (sigma 17)
  • .vbs corpus 18 (sigma 18)
field:"TargetFilename" kind:ends_with
TargetFilenamematch
  • \15\TEMPLATE\LAYOUTS\ corpus 2 (sigma 2)
  • \16\TEMPLATE\LAYOUTS\ corpus 2 (sigma 2)
field:"TargetFilename" kind:match
TargetFilenamestarts_with
  • C:\Program Files (x86)\Common Files\Microsoft Shared\Web Server Extensions\ corpus 2 (sigma 2)
  • C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\ corpus 2 (sigma 2)
field:"TargetFilename" kind:starts_with

Suspicious IIS Module Registration

#
Status
test
Severity
high
Author
Florian Roth (Nextron Systems), Microsoft (idea)
Source
github.com/SigmaHQ/sigma

Detects a suspicious IIS module registration as described in Microsoft threat report on IIS backdoors

Known False Positives

  • Administrative activity

MITRE ATT&CK Coverage

Telemetry Coverage

Rule Body

title: Suspicious IIS Module Registration
id: 043c4b8b-3a54-4780-9682-081cb6b8185c
status: test
description: Detects a suspicious IIS module registration as described in Microsoft threat report on IIS backdoors
references:
    - https://www.microsoft.com/security/blog/2022/07/26/malicious-iis-extensions-quietly-open-persistent-backdoors-into-servers/
author: Florian Roth (Nextron Systems), Microsoft (idea)
date: 2022-08-04
modified: 2023-01-23
tags:
    - attack.persistence
    - attack.t1505.004
logsource:
    category: process_creation
    product: windows
detection:
    selection_parent:
        ParentImage|endswith: '\w3wp.exe'
    selection_cli_1:
        CommandLine|contains: 'appcmd.exe add module'
    selection_cli_2:
        CommandLine|contains: ' system.enterpriseservices.internal.publish'
        Image|endswith: '\powershell.exe'
    selection_cli_3:
        CommandLine|contains|all:
            - 'gacutil'
            - ' /I'
    condition: selection_parent and 1 of selection_cli_*
falsepositives:
    - Administrative activity
level: high

Stages and Predicates

Stage 0: condition

selection_parent and 1 of selection_cli_*

Stage 1: selection_parent

selection_parent:
    ParentImage|endswith: '\w3wp.exe'

Stage 2: selection_cli_1

selection_cli_1:
    CommandLine|contains: 'appcmd.exe add module'

Stage 3: selection_cli_2

selection_cli_2:
    CommandLine|contains: ' system.enterpriseservices.internal.publish'
    Image|endswith: '\powershell.exe'

Stage 4: selection_cli_3

selection_cli_3:
    CommandLine|contains|all:
        - 'gacutil'
        - ' /I'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • /I corpus 2 (sigma 2)
  • system.enterpriseservices.internal.publish
  • appcmd.exe add module
  • gacutil
field:"CommandLine" kind:match
Imageends_with
  • \powershell.exe corpus 181 (sigma 180, splunk 1)
field:"Image" kind:ends_with value:"\powershell.exe"
ParentImageends_with
  • \w3wp.exe corpus 12 (sigma 12)
field:"ParentImage" kind:ends_with value:"\w3wp.exe"

Suspicious PowerShell Mailbox Export to Share

#
Status
test
Severity
critical
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects usage of the powerShell New-MailboxExportRequest Cmdlet to exports a mailbox to a remote or local share, as used in ProxyShell exploitations

MITRE ATT&CK Coverage

TacticTechniques
ExfiltrationNo specific technique

Telemetry Coverage

Rule Body

title: Suspicious PowerShell Mailbox Export to Share
id: 889719ef-dd62-43df-86c3-768fb08dc7c0
status: test
description: Detects usage of the powerShell New-MailboxExportRequest Cmdlet to exports a mailbox to a remote or local share, as used in ProxyShell exploitations
references:
    - https://youtu.be/5mqid-7zp8k?t=2481
    - https://blog.orange.tw/2021/08/proxylogon-a-new-attack-surface-on-ms-exchange-part-1.html
    - https://peterjson.medium.com/reproducing-the-proxyshell-pwn2own-exploit-49743a4ea9a1
    - https://m365internals.com/2022/10/07/hunting-in-on-premises-exchange-server-logs/
author: Florian Roth (Nextron Systems)
date: 2021-08-07
modified: 2022-10-26
tags:
    - attack.exfiltration
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains|all:
            - 'New-MailboxExportRequest'
            - ' -Mailbox '
            - ' -FilePath \\\\'
    condition: selection
falsepositives:
    - Unknown
level: critical

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    CommandLine|contains|all:
        - 'New-MailboxExportRequest'
        - ' -Mailbox '
        - ' -FilePath \\\\'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • -FilePath \\\\
  • -Mailbox
  • New-MailboxExportRequest
field:"CommandLine" kind:match

Sysmon File Executable Creation Detected

#
Status
test
Severity
medium
Author
frack113
Source
github.com/SigmaHQ/sigma

Detects Portable Executable (PE) files creation events logged by Sysmon in paths monitored by the used Sysmon configuration. This is a high-value detection for catching unauthorized or suspicious executable drops. Alert volume and scope depend entirely on which paths or files are monitored in the Sysmon config. A high noise level or hits from known-legitimate software are a strong signal that the Sysmon configuration is too permissive, not that the detection itself is wrong and probably needs to be tuned to a more restrictive set of paths or files.

Known False Positives

  • Legitimate software writing executables to monitored paths - if this occurs, narrow the Sysmon configuration to more sensitive paths rather than suppressing this rule

MITRE ATT&CK Coverage

TacticTechniques
Defense ImpairmentNo specific technique

Telemetry Coverage

Rule Body

title: Sysmon File Executable Creation Detected
id: 693a44e9-7f26-4cb6-b787-214867672d3a
status: test
description: |
    Detects Portable Executable (PE) files creation events logged by Sysmon in paths monitored by the used Sysmon configuration.
    This is a high-value detection for catching unauthorized or suspicious executable drops.
    Alert volume and scope depend entirely on which paths or files are monitored in the Sysmon config.
    A high noise level or hits from known-legitimate software are a strong signal that the Sysmon configuration is too permissive, not that the detection itself is wrong and probably needs to be tuned to a more restrictive set of paths or files.
references:
    - https://learn.microsoft.com/en-us/sysinternals/downloads/sysmon
    - https://medium.com/@olafhartong/sysmon-15-0-file-executable-detected-40fd64349f36
author: frack113
date: 2023-07-20
tags:
    - attack.defense-impairment
logsource:
    product: windows
    service: sysmon
detection:
    selection:
        EventID: 29  # this is fine, we want to match any FileExecutableDetected event
    condition: selection
falsepositives:
    - Legitimate software writing executables to monitored paths - if this occurs, narrow the Sysmon configuration to more sensitive paths rather than suppressing this rule
level: medium
regression_tests_path: regression_data/rules/windows/sysmon/sysmon_file_executable_detected/info.yml

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    EventID: 29

UAC Bypass Using Event Viewer RecentViews

#
Status
test
Severity
high
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the pattern of UAC Bypass using Event Viewer RecentViews

MITRE ATT&CK Coverage

TacticTechniques
Privilege EscalationNo specific technique
StealthNo specific technique

Telemetry Coverage

Rule Body

title: UAC Bypass Using Event Viewer RecentViews
id: 30fc8de7-d833-40c4-96b6-28319fbc4f6c
related:
    - id: 63e4f530-65dc-49cc-8f80-ccfa95c69d43
      type: similar
status: test
description: Detects the pattern of UAC Bypass using Event Viewer RecentViews
references:
    - https://twitter.com/orange_8361/status/1518970259868626944
    - https://lolbas-project.github.io/lolbas/Binaries/Eventvwr/#execute
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-11-22
tags:
    - attack.privilege-escalation
    - attack.stealth
logsource:
    category: process_creation
    product: windows
detection:
    selection_path:
        # Example: ysoserial.exe -o raw -f BinaryFormatter - g DataSet -c calc > RecentViews & copy RecentViews %LOCALAPPDATA%\Microsoft\EventV~1\RecentViews & eventvwr.exe
        CommandLine|contains:
            - '\Event Viewer\RecentViews'
            - '\EventV~1\RecentViews'
    selection_redirect:
        CommandLine|contains: '>'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_path

selection_path:
    CommandLine|contains:
        - '\Event Viewer\RecentViews'
        - '\EventV~1\RecentViews'

Stage 2: selection_redirect

selection_redirect:
    CommandLine|contains: '>'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • > corpus 6 (sigma 6)
  • \Event Viewer\RecentViews
  • \EventV~1\RecentViews
field:"CommandLine" kind:match

Uncommon Child Process Of Setres.EXE

#
Status
test
Severity
high
Author
@gott_cyber, Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects uncommon child process of Setres.EXE. Setres.EXE is a Windows server only process and tool that can be used to set the screen resolution. It can potentially be abused in order to launch any arbitrary file with a name containing the word "choice" from the current execution path.

Known False Positives

  • Unlikely

MITRE ATT&CK Coverage

Telemetry Coverage

Rule Body

title: Uncommon Child Process Of Setres.EXE
id: 835e75bf-4bfd-47a4-b8a6-b766cac8bcb7
status: test
description: |
    Detects uncommon child process of Setres.EXE.
    Setres.EXE is a Windows server only process and tool that can be used to set the screen resolution.
    It can potentially be abused in order to launch any arbitrary file with a name containing the word "choice" from the current execution path.
references:
    - https://lolbas-project.github.io/lolbas/Binaries/Setres/
    - https://twitter.com/0gtweet/status/1583356502340870144
    - https://strontic.github.io/xcyclopedia/library/setres.exe-0E30E4C09637D7A128A37B59A3BC4D09.html
    - https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/cc731033(v=ws.11)
author: '@gott_cyber, Nasreddine Bencherchali (Nextron Systems)'
date: 2022-12-11
modified: 2024-06-26
tags:
    - attack.stealth
    - attack.t1218
    - attack.t1202
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\setres.exe'
        Image|contains: '\choice'
    filter_main_legit_location:
        Image|endswith:
            - 'C:\Windows\System32\choice.exe'
            - 'C:\Windows\SysWOW64\choice.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    ParentImage|endswith: '\setres.exe'
    Image|contains: '\choice'

Stage 2: not filter_main_legit_location

filter_main_legit_location:
    Image|endswith:
        - 'C:\Windows\System32\choice.exe'
        - 'C:\Windows\SysWOW64\choice.exe'

Indicators

These rows show field, operator, and value matches.

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
Imageends_withC:\Windows\SysWOW64\choice.exeexcludes:Image field:"Image" value:"C:\Windows\SysWOW64\choice.exe"
Imageends_withC:\Windows\System32\choice.exeexcludes:Image field:"Image" value:"C:\Windows\System32\choice.exe"

VMGuestLib DLL Sideload

#
Status
test
Severity
medium
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects DLL sideloading of VMGuestLib.dll by the WmiApSrv service.

Known False Positives

  • FP could occur if the legitimate version of vmGuestLib already exists on the system

MITRE ATT&CK Coverage

Telemetry Coverage

ProviderRecord / event type
SysmonEvent ID 7: Image loaded

Rule Body

title: VMGuestLib DLL Sideload
id: 70e8e9b4-6a93-4cb7-8cde-da69502e7aff
status: test
description: Detects DLL sideloading of VMGuestLib.dll by the WmiApSrv service.
references:
    - https://decoded.avast.io/martinchlumecky/png-steganography/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-12-01
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|contains|all:
            - '\VMware\VMware Tools\vmStatsProvider\win32'
            - '\vmGuestLib.dll'
        Image|endswith: '\Windows\System32\wbem\WmiApSrv.exe'
    filter:
        Signed: 'true'
    condition: selection and not filter
falsepositives:
    - FP could occur if the legitimate version of vmGuestLib already exists on the system
level: medium

Stages and Predicates

Stage 0: condition

selection and not filter

Stage 1: selection

selection:
    ImageLoaded|contains|all:
        - '\VMware\VMware Tools\vmStatsProvider\win32'
        - '\vmGuestLib.dll'
    Image|endswith: '\Windows\System32\wbem\WmiApSrv.exe'

Stage 2: not filter

filter:
    Signed: 'true'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Imageends_with
  • \Windows\System32\wbem\WmiApSrv.exe
field:"Image" kind:ends_with value:"\Windows\System32\wbem\WmiApSrv.exe"
ImageLoadedmatch
  • \VMware\VMware Tools\vmStatsProvider\win32
  • \vmGuestLib.dll
field:"ImageLoaded" kind:match

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
Signedeqtrueexcludes:Signed field:"Signed" value:"true"

Wget Creating Files in Tmp Directory

#
Status
test
Severity
medium
Author
Joseliyo Sanchez, @Joseliyo_Jstnk
Source
github.com/SigmaHQ/sigma

Detects the use of wget to download content in a temporary directory such as "/tmp" or "/var/tmp"

Known False Positives

  • Legitimate downloads of files in the tmp folder.

MITRE ATT&CK Coverage

TacticTechniques
Command & Control

Telemetry Coverage

PlatformRecord / event type
LinuxEvent ID 11: File created

Rule Body

title: Wget Creating Files in Tmp Directory
id: 35a05c60-9012-49b6-a11f-6bab741c9f74
status: test
description: Detects the use of wget to download content in a temporary directory such as "/tmp" or "/var/tmp"
references:
    - https://blogs.jpcert.or.jp/en/2023/05/gobrat.html
    - https://jstnk9.github.io/jstnk9/research/GobRAT-Malware/
    - https://www.virustotal.com/gui/file/60bcd645450e4c846238cf0e7226dc40c84c96eba99f6b2cffcd0ab4a391c8b3/detection
    - https://www.virustotal.com/gui/file/3e44c807a25a56f4068b5b8186eee5002eed6f26d665a8b791c472ad154585d1/detection
author: Joseliyo Sanchez, @Joseliyo_Jstnk
date: 2023-06-02
tags:
    - attack.command-and-control
    - attack.t1105
logsource:
    product: linux
    category: file_event
detection:
    selection:
        Image|endswith: '/wget'
        TargetFilename|startswith:
            - '/tmp/'
            - '/var/tmp/'
    condition: selection
falsepositives:
    - Legitimate downloads of files in the tmp folder.
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    Image|endswith: '/wget'
    TargetFilename|startswith:
        - '/tmp/'
        - '/var/tmp/'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Imageends_with
  • /wget corpus 14 (sigma 14)
field:"Image" kind:ends_with value:"/wget"
TargetFilenamestarts_with
  • /tmp/ corpus 9 (elastic 8, sigma 1)
  • /var/tmp/ corpus 8 (elastic 7, sigma 1)
field:"TargetFilename" kind:starts_with

Back to all Sigma rules