Detection rules › Kusto

Gain Code Execution on ADFS Server via Remote WMI Execution

Severity
medium
Time window
7d
Group by
TargetLogonId
Author
Microsoft Security Research
Source
github.com/Azure/Azure-Sentinel

This query detects instances where an attacker has gained the ability to execute code on an ADFS Server through remote WMI Execution. In order to use this query you need to be collecting Sysmon EventIDs 19, 20, and 21. If you do not have Sysmon data in your workspace this query will raise an error stating: Failed to resolve scalar expression named "[@Name]" For more on how WMI was used in Solorigate see https://www.microsoft.com/security/blog/2021/01/20/deep-dive-into-the-solorigate-second-stage-activation-from-sunburst-to-teardrop-and-raindrop/. The query contains some features from the following detections to look for potentially malicious ADFS activity. See them for more details. - ADFS DKM Master Key Export: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/ADFS-DKM-MasterKey-Export.yaml

MITRE ATT&CK coverage

TacticTechniques
Lateral Movement

Telemetry coverage

Rule body

id: 0bd65651-1404-438b-8f63-eecddcec87b4
name: Gain Code Execution on ADFS Server via Remote WMI Execution
description: |
   'This query detects instances where an attacker has gained the ability to execute code on an ADFS Server through remote WMI Execution.
   In order to use this query you need to be collecting Sysmon EventIDs 19, 20, and 21.
   If you do not have Sysmon data in your workspace this query will raise an error stating:
        Failed to resolve scalar expression named "[@Name]"
   For more on how WMI was used in Solorigate see https://www.microsoft.com/security/blog/2021/01/20/deep-dive-into-the-solorigate-second-stage-activation-from-sunburst-to-teardrop-and-raindrop/.
   The query contains some features from the following detections to look for potentially malicious ADFS activity. See them for more details.
   - ADFS DKM Master Key Export: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/ADFS-DKM-MasterKey-Export.yaml'
severity: Medium
requiredDataConnectors:
  - connectorId: SecurityEvents
    dataTypes:
      - SecurityEvent
  - connectorId: WindowsSecurityEvents
    dataTypes: 
      - SecurityEvents 
  - connectorId: WindowsForwardedEvents
    dataTypes: 
      - WindowsEvent 
queryFrequency: 1d
queryPeriod: 7d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - LateralMovement
relevantTechniques:
  - T1210
tags:
  - Solorigate
  - NOBELIUM
query: |
  let timeframe = 1d;
  // Adjust for a longer timeframe for identifying ADFS Servers
  let lookback = 6d;
  // Identify ADFS Servers
  let ADFS_Servers = ( union isfuzzy=true
  ( Event
  | where TimeGenerated > ago(timeframe+lookback)
  | where Source == "Microsoft-Windows-Sysmon"
  | where EventID == 1
  | extend EventData = parse_xml(EventData).DataItem.EventData.Data
  | mv-expand bagexpansion=array EventData
  | evaluate bag_unpack(EventData)
  | extend Key=tostring(['@Name']), Value=['#text']
  | evaluate pivot(Key, any(Value), TimeGenerated, Source, EventLog, Computer, EventLevel, EventLevelName, UserName, RenderedDescription, MG, ManagementGroupName, Type, _ResourceId)
  | extend process = split(Image, '\\', -1)[-1]
  | where process =~ "Microsoft.IdentityServer.ServiceHost.exe"
  | distinct Computer
  ),
  ( SecurityEvent
  | where TimeGenerated > ago(timeframe+lookback)
  | where EventID == 4688 and SubjectLogonId != "0x3e4"
  | where ProcessName has "Microsoft.IdentityServer.ServiceHost.exe"
  | distinct Computer
  ),
  (WindowsEvent
  | where TimeGenerated > ago(timeframe+lookback)
  | where EventID == 4688 and EventData has "0x3e4" and EventData has "Microsoft.IdentityServer.ServiceHost.exe"
  | extend SubjectLogonId  = tostring(EventData.SubjectLogonId)
  | where SubjectLogonId != "0x3e4"
  | extend ProcessName  = tostring(EventData.ProcessName)
  | where ProcessName has "Microsoft.IdentityServer.ServiceHost.exe"
  | distinct Computer
  )
  | distinct Computer);
  (union isfuzzy=true
  (
  SecurityEvent
  | where EventID == 4688
  | where TimeGenerated > ago(timeframe)
  | where Computer in~ (ADFS_Servers)
  | where ParentProcessName has 'wmiprvse.exe'
  // Looking for rundll32.exe is based on intel from the blog linked in the description
  // This can be commented out or altered to filter out known internal uses
  | where CommandLine has_any ('rundll32') 
  | project TimeGenerated, TargetAccount, CommandLine, Computer, Account, TargetLogonId
  | extend timestamp = TimeGenerated
  | extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
  | extend AccountName = tostring(split(Account, "\\")[0]), AccountNTDomain = tostring(split(Account, "\\")[1])
  // Search for recent logons to identify lateral movement
  | join kind= inner
  (SecurityEvent
  | where TimeGenerated > ago(timeframe)
  | where EventID == 4624 and LogonType == 3
  | where Account !endswith "$"
  | project TargetLogonId
  ) on TargetLogonId
  ),
  (
  WindowsEvent
  | where EventID == 4688
  | where TimeGenerated > ago(timeframe)
  | where Computer in~ (ADFS_Servers)
  | where EventData has 'wmiprvse.exe' and EventData has_any ('rundll32') 
  | extend ParentProcessName = tostring(EventData.ParentProcessName)
  | where ParentProcessName has 'wmiprvse.exe'
  // Looking for rundll32.exe is based on intel from the blog linked in the description
  // This can be commented out or altered to filter out known internal uses
  | extend CommandLine = tostring(EventData.CommandLine)
  | where CommandLine has_any ('rundll32') 
  | extend TargetAccount = strcat(EventData.TargetDomainName,"\\", EventData.TargetUserName)
  | extend Account = strcat(EventData.TargetDomainName,"\\", EventData.TargetUserName)
  | extend TargetLogonId = tostring(EventData.TargetLogonId)
  | project TimeGenerated, TargetAccount, CommandLine, Computer, Account, TargetLogonId
  | extend timestamp = TimeGenerated
  | extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
  | extend AccountName = tostring(split(Account, "\\")[0]), AccountNTDomain = tostring(split(Account, "\\")[1])
  // Search for recent logons to identify lateral movement
  | join kind= inner
  (WindowsEvent
  | where TimeGenerated > ago(timeframe)
  | where EventID == 4624 
  | extend  LogonType = tostring(EventData.LogonType)
  | where LogonType == 3
  | extend Account = strcat(EventData.TargetDomainName,"\\", EventData.TargetUserName)
  | where Account !endswith "$"
  | extend TargetLogonId = tostring(EventData.TargetLogonId)
  | project TargetLogonId
  ) on TargetLogonId
  ),
  (
  Event
  | where TimeGenerated > ago(timeframe)
  | where Source == "Microsoft-Windows-Sysmon"
  // Check for WMI Events
  | where Computer in~ (ADFS_Servers) and EventID in (19, 20, 21)
  | extend EventData = parse_xml(EventData).DataItem.EventData.Data
  | mv-expand bagexpansion=array EventData
  | evaluate bag_unpack(EventData)
  | extend Key=tostring(['@Name']), Value=['#text']
  | evaluate pivot(Key, any(Value), TimeGenerated, Source, EventLog, Computer, EventLevel, EventLevelName, UserName, RenderedDescription, MG, ManagementGroupName, Type, _ResourceId)
  | project TimeGenerated, EventType, Image, Computer, UserName
  | extend timestamp = TimeGenerated
  | extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
  | extend AccountName = tostring(split(UserName, "\\")[0]), AccountNTDomain = tostring(split(UserName, "\\")[1])
  )
  )
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: UserName
      - identifier: Name
        columnName: AccountName
      - identifier: NTDomain
        columnName: AccountNTDomain
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: Computer
      - identifier: HostName
        columnName: HostName
      - identifier: NTDomain
        columnName: HostNameDomain
version: 1.1.4
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: Microsoft Security Research
    support:
        tier: Community
    categories:
        domains: [ "Security - Others", "Identity" ]

Stages and Predicates

Parameters

let timeframe = 1d;
let lookback = 6d;

Let binding: ADFS_Servers

let ADFS_Servers = ( union isfuzzy=true
( Event
| where TimeGenerated > ago(timeframe+lookback)
| where Source == "Microsoft-Windows-Sysmon"
| where EventID == 1
| extend EventData = parse_xml(EventData).DataItem.EventData.Data
| mv-expand bagexpansion=array EventData
| evaluate bag_unpack(EventData)
| extend Key=tostring(['@Name']), Value=['#text']
| evaluate pivot(Key, any(Value), TimeGenerated, Source, EventLog, Computer, EventLevel, EventLevelName, UserName, RenderedDescription, MG, ManagementGroupName, Type, _ResourceId)
| extend process = split(Image, '\\', -1)[-1]
| where process =~ "Microsoft.IdentityServer.ServiceHost.exe"
| distinct Computer
),
( SecurityEvent
| where TimeGenerated > ago(timeframe+lookback)
| where EventID == 4688 and SubjectLogonId != "0x3e4"
| where ProcessName has "Microsoft.IdentityServer.ServiceHost.exe"
| distinct Computer
),
(WindowsEvent
| where TimeGenerated > ago(timeframe+lookback)
| where EventID == 4688 and EventData has "0x3e4" and EventData has "Microsoft.IdentityServer.ServiceHost.exe"
| extend SubjectLogonId  = tostring(EventData.SubjectLogonId)
| where SubjectLogonId != "0x3e4"
| extend ProcessName  = tostring(EventData.ProcessName)
| where ProcessName has "Microsoft.IdentityServer.ServiceHost.exe"
| distinct Computer
)
| distinct Computer);

union isfuzzy=true (3 sources)

Each leg below queries one source; the rule matches if any leg does. Sources: SecurityEvent, WindowsEvent, Event

Leg 1: SecurityEvent

SecurityEvent
| where EventID == 4688
| where TimeGenerated > ago(timeframe)
| where Computer in~ (ADFS_Servers)
| where ParentProcessName has 'wmiprvse.exe'
| where CommandLine has_any ('rundll32') 
| project TimeGenerated, TargetAccount, CommandLine, Computer, Account, TargetLogonId
| extend timestamp = TimeGenerated
| extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
| extend AccountName = tostring(split(Account, "\\")[0]), AccountNTDomain = tostring(split(Account, "\\")[1])
| join kind= inner
(SecurityEvent
| where TimeGenerated > ago(timeframe)
| where EventID == 4624 and LogonType == 3
| where Account !endswith "$"
| project TargetLogonId
) on TargetLogonId

Leg 2: WindowsEvent

WindowsEvent
| where EventID == 4688
| where TimeGenerated > ago(timeframe)
| where Computer in~ (ADFS_Servers)
| where EventData has 'wmiprvse.exe' and EventData has_any ('rundll32') 
| extend ParentProcessName = tostring(EventData.ParentProcessName)
| where ParentProcessName has 'wmiprvse.exe'
| extend CommandLine = tostring(EventData.CommandLine)
| where CommandLine has_any ('rundll32') 
| extend TargetAccount = strcat(EventData.TargetDomainName,"\\", EventData.TargetUserName)
| extend Account = strcat(EventData.TargetDomainName,"\\", EventData.TargetUserName)
| extend TargetLogonId = tostring(EventData.TargetLogonId)
| project TimeGenerated, TargetAccount, CommandLine, Computer, Account, TargetLogonId
| extend timestamp = TimeGenerated
| extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
| extend AccountName = tostring(split(Account, "\\")[0]), AccountNTDomain = tostring(split(Account, "\\")[1])
| join kind= inner
(WindowsEvent
| where TimeGenerated > ago(timeframe)
| where EventID == 4624 
| extend  LogonType = tostring(EventData.LogonType)
| where LogonType == 3
| extend Account = strcat(EventData.TargetDomainName,"\\", EventData.TargetUserName)
| where Account !endswith "$"
| extend TargetLogonId = tostring(EventData.TargetLogonId)
| project TargetLogonId
) on TargetLogonId

Leg 3: Event

Event
| where TimeGenerated > ago(timeframe)
| where Source == "Microsoft-Windows-Sysmon"
| where Computer in~ (ADFS_Servers) and EventID in (19, 20, 21)
| extend EventData = parse_xml(EventData).DataItem.EventData.Data
| mv-expand bagexpansion=array EventData
| evaluate bag_unpack(EventData)
| extend Key=tostring(['@Name']), Value=['#text']
| evaluate pivot(Key, any(Value), TimeGenerated, Source, EventLog, Computer, EventLevel, EventLevelName, UserName, RenderedDescription, MG, ManagementGroupName, Type, _ResourceId)
| project TimeGenerated, EventType, Image, Computer, UserName
| extend timestamp = TimeGenerated
| extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
| extend AccountName = tostring(split(UserName, "\\")[0]), AccountNTDomain = tostring(split(UserName, "\\")[1])

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
Accountends_with$excludes:Account field:"Account" value:"$"

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • rundll32 transforms: term corpus 26 (sigma 23, chronicle 2, kusto 1)
field:"CommandLine" kind:match value:"rundll32"
Computerin
  • ADFS_Servers corpus 5 (kusto 5)
field:"Computer" kind:in value:"ADFS_Servers"
EventDatamatch
  • rundll32 transforms: term
  • wmiprvse.exe transforms: term
field:"EventData" kind:match
EventIDeq
  • 4624 corpus 29 (splunk 13, kusto 11, chronicle 4, elastic 1)
  • 4688 corpus 317 (splunk 283, kusto 33, elastic 1)
field:"EventID" kind:eq
EventIDin
  • 19
  • 20
  • 21 corpus 2 (elastic 1, splunk 1)
field:"EventID" kind:in
LogonTypeeq
  • 3 corpus 41 (splunk 13, sigma 12, elastic 9, kusto 7)
field:"LogonType" kind:eq value:"3"
ParentProcessNamematch
  • wmiprvse.exe transforms: term
field:"ParentImage" kind:match value:"wmiprvse.exe"

Output fields

These fields are emitted when the rule matches.

FieldSource
Computerproject
EventTypeproject
Imageproject
TimeGeneratedproject
UserNameproject
timestampextend
DomainIndexextend
HostNameextend
HostNameDomainextend
AccountNTDomainextend
AccountNameextend