Detection rules › Kusto
Dev-0228 File Path Hashes November 2021 (ASIM Version)
This hunting query looks for file paths/hashes related to observed activity by Dev-0228. The actor is known to use custom version of popular tool like PsExec, Procdump etc. to carry its activity. The risk score associated with each result is based on a number of factors, hosts with higher risk events should be investigated first. This query uses the Microsoft Sentinel Information Model - https://docs.microsoft.com/azure/sentinel/normalization
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1569 System Services |
| Credential Access | T1003 OS Credential Dumping |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Sysmon | Event ID 5 | Process terminated |
| Security-Auditing | Event ID 4688 | A new process has been created. |
| Security-Auditing | Event ID 4689 | A process has exited. |
Rule body kusto
id: 29a29e5d-354e-4f5e-8321-8b39d25047bf
name: Dev-0228 File Path Hashes November 2021 (ASIM Version)
description: |
'This hunting query looks for file paths/hashes related to observed activity by Dev-0228. The actor is known to use custom version of popular tool like PsExec, Procdump etc. to carry its activity.
The risk score associated with each result is based on a number of factors, hosts with higher risk events should be investigated first.
This query uses the Microsoft Sentinel Information Model - https://docs.microsoft.com/azure/sentinel/normalization'
severity: High
requiredDataConnectors: []
queryFrequency: 6h
queryPeriod: 6h
triggerOperator: gt
triggerThreshold: 0
tactics:
- CredentialAccess
- Execution
relevantTechniques:
- T1569
- T1003
query: |
let files1 = dynamic(["C:\\Windows\\TAPI\\lsa.exe", "C:\\Windows\\TAPI\\pa.exe", "C:\\Windows\\TAPI\\pc.exe", "C:\\Windows\\TAPI\\Rar.exe"]);
let files2 = dynamic(["svchost.exe","wdmsvc.exe"]);
let FileHash1 = dynamic(["43109fbe8b752f7a9076eaafa417d9ae5c6e827cd5374b866672263fdebd5ec3", "ab50d8d707b97712178a92bbac74ccc2a5699eb41c17aa77f713ff3e568dcedb", "010e32be0f86545e116a8bc3381a8428933eb8789f32c261c81fd5e7857d4a77", "56cd102b9fc7f3523dad01d632525ff673259dbc9a091be0feff333c931574f7"]);
let FileHash2 = dynamic(["2a1044e9e6e87a032f80c6d9ea6ae61bbbb053c0a21b186ecb3b812b49eb03b7", "9ab7e99ed84f94a7b6409b87e56dc6e1143b05034a5e4455e8c555dbbcd0d2dd", "18a072ccfab239e140d8f682e2874e8ff19d94311fc8bb9564043d3e0deda54b"]);
imProcessCreate
| where ((Process has_any (files1)) and (ActingProcessSHA256 has_any (FileHash1))) or ((Process has_any (files2)) and (ActingProcessSHA256 has_any (FileHash2)))
// Increase risk score if recent alerts for the host
| join kind=leftouter (
SecurityAlert
| where ProviderName =~ "MDATP"
| extend ThreatName = tostring(parse_json(ExtendedProperties).ThreatName)
| mv-expand todynamic(Entities)
| extend DvcId = tostring(parse_json(Entities).MdatpDeviceId)
| where isnotempty(DvcId)
// Higher risk score are for Defender alerts related to threat actor
| extend AlertRiskScore = iif(ThreatName has_any ("Backdoor:MSIL/ShellClient.A", "Backdoor:MSIL/ShellClient.A!dll", "Trojan:MSIL/Mimikatz.BA!MTB"), 1.0, 0.5)
| project DvcId, AlertRiskScore)
on DvcId
| extend AlertRiskScore = iif(isempty(AlertRiskScore), 0.0, AlertRiskScore)
| extend AccountName = tostring(split(ActorUsername, @'\')[1]), AccountNTDomain = tostring(split(ActorUsername, @'\')[0])
| extend HostName = tostring(split(Dvc, ".")[0]), DomainIndex = toint(indexof(Dvc, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Dvc, DomainIndex + 1), Dvc)
| project-away DomainIndex
entityMappings:
- entityType: Account
fieldMappings:
- identifier: FullName
columnName: ActorUsername
- identifier: Name
columnName: AccountName
- identifier: NTDomain
columnName: AccountNTDomain
- entityType: Host
fieldMappings:
- identifier: FullName
columnName: Dvc
- identifier: HostName
columnName: HostName
- identifier: DnsDomain
columnName: HostNameDomain
- entityType: File
fieldMappings:
- identifier: Name
columnName: ActingProcessFilename
version: 1.2.3
kind: Scheduled
metadata:
source:
kind: Community
author:
name: Microsoft Security Research
support:
tier: Community
categories:
domains: [ "Security - Threat Intelligence" ]
Stages and Predicates
Parameters
let files1 = dynamic(["C:\\Windows\\TAPI\\lsa.exe", "C:\\Windows\\TAPI\\pa.exe", "C:\\Windows\\TAPI\\pc.exe", "C:\\Windows\\TAPI\\Rar.exe"]);
let files2 = dynamic(["svchost.exe","wdmsvc.exe"]);
Let binding: FileHash1
let FileHash1 = dynamic(["43109fbe8b752f7a9076eaafa417d9ae5c6e827cd5374b866672263fdebd5ec3", "ab50d8d707b97712178a92bbac74ccc2a5699eb41c17aa77f713ff3e568dcedb", "010e32be0f86545e116a8bc3381a8428933eb8789f32c261c81fd5e7857d4a77", "56cd102b9fc7f3523dad01d632525ff673259dbc9a091be0feff333c931574f7"]);
Let binding: FileHash2
let FileHash2 = dynamic(["2a1044e9e6e87a032f80c6d9ea6ae61bbbb053c0a21b186ecb3b812b49eb03b7", "9ab7e99ed84f94a7b6409b87e56dc6e1143b05034a5e4455e8c555dbbcd0d2dd", "18a072ccfab239e140d8f682e2874e8ff19d94311fc8bb9564043d3e0deda54b"]);
Stage 1: source
imProcessCreate
Stage 2: where
| where ((Process has_any (files1)) and (ActingProcessSHA256 has_any (FileHash1))) or ((Process has_any (files2)) and (ActingProcessSHA256 has_any (FileHash2)))
References FileHash1, FileHash2 (defined above).
Stage 3: join
| join kind=leftouter (
SecurityAlert
| where ProviderName =~ "MDATP"
| extend ThreatName = tostring(parse_json(ExtendedProperties).ThreatName)
| mv-expand todynamic(Entities)
| extend DvcId = tostring(parse_json(Entities).MdatpDeviceId)
| where isnotempty(DvcId)
| extend AlertRiskScore = iif(ThreatName has_any ("Backdoor:MSIL/ShellClient.A", "Backdoor:MSIL/ShellClient.A!dll", "Trojan:MSIL/Mimikatz.BA!MTB"), 1.0, 0.5)
| project DvcId, AlertRiskScore)
on DvcId
Stage 4: extend (4 consecutive steps)
| extend AlertRiskScore = iif(isempty(AlertRiskScore), 0.0, AlertRiskScore)
| extend AccountName = tostring(split(ActorUsername, @'\')[1]), AccountNTDomain = tostring(split(ActorUsername, @'\')[0])
| extend HostName = tostring(split(Dvc, ".")[0]), DomainIndex = toint(indexof(Dvc, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Dvc, DomainIndex + 1), Dvc)
Stage 5: project-away
| project-away DomainIndex
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
ActingProcessSHA256 | match |
|
DvcId | is_not_null | |
Process | match |
|
ProviderName | eq |
|
Output fields
Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.
| Field | Source |
|---|---|
AlertRiskScore | extend |
AccountNTDomain | extend |
AccountName | extend |
HostName | extend |
HostNameDomain | extend |