Semperis DSP Well-known privileged SIDs in sIDHistory

Status: available
Severity: medium
Time window: 1h
Source: github.com/Azure/Azure-Sentinel

'This indicator looks for security principals that contain specific SIDs of accounts from built-in privileged groups within their sIDHistory attribute. This would allow those security principals to have the same privileges as those privileged accounts, but in a way that is not obvious to monitor (e.g. through group membership).'

MITRE ATT&CK coverage

Tactic	Techniques
Privilege Escalation	`T1134` Access Token Manipulation
Stealth	`T1134` Access Token Manipulation

Rule body

id: ddd75d93-5b8b-4349-babe-c4e15343c5a3
name: Semperis DSP Well-known privileged SIDs in sIDHistory
description: |
  'This indicator looks for security principals that contain specific SIDs of accounts from built-in privileged groups within their sIDHistory attribute. This would allow those security principals to have the same privileges as those privileged accounts, but in a way that is not obvious to monitor (e.g. through group membership).'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: SemperisDSP
    dataTypes:
      - dsp_parser
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - PrivilegeEscalation
  - DefenseEvasion
relevantTechniques:
  - T1134
query: |
  dsp_parser
  | where EventID == 9212
  | where SecurityIndicatorName == "Well-known privileged SIDs in sIDHistory"
  | extend HostName = tostring(split(Computer, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(Computer, '.'), 1, -1), '.'))
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: HostName
        columnName: HostName
      - identifier: DnsDomain
        columnName: DnsDomain
version: 2.0.7
kind: Scheduled

Stages and Predicates

Stage 1: `source`

dsp_parser

Stage 2: `where`

| where EventID == 9212

Stage 3: `where`

| where SecurityIndicatorName == "Well-known privileged SIDs in sIDHistory"

Stage 4: `extend`

| extend HostName = tostring(split(Computer, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(Computer, '.'), 1, -1), '.'))

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`EventID`	eq	`9212`	`field:"EventID" kind:eq value:"9212"`
`SecurityIndicatorName`	eq	`Well-known privileged SIDs in sIDHistory`	`field:"SecurityIndicatorName" kind:eq value:"Well-known privileged SIDs in sIDHistory"`

Output fields

These fields are emitted when the rule matches.

Field	Source
`DnsDomain`	`extend`
`HostName`	`extend`