Semperis DSP Mimikatz's DCShadow Alert

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

'Mimikatz's DCShadow switch allows a user who has compromised an AD domain, to inject arbitrary changes into AD using a "fake" domain controller. These changes bypass the security event log and can't be spotted using normal AD tools. This rule looks for evidence that a machine has been used in this capacity.'

MITRE ATT&CK coverage

Tactic	Techniques
Defense Impairment	`T1207` Rogue Domain Controller

Rule body

id: 1a6d0a49-64b3-4ca1-96c3-f154c16c218c
name: Semperis DSP Mimikatz's DCShadow Alert
description: |
  'Mimikatz's DCShadow switch allows a user who has compromised an AD domain, to inject arbitrary changes into AD using a "fake" domain controller. These changes bypass the security event log and can't be spotted using normal AD tools. This rule looks for evidence that a machine has been used in this capacity.'
severity: High
status: Available
requiredDataConnectors:
  - connectorId: SemperisDSP
    dataTypes:
      - dsp_parser
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - DefenseEvasion
relevantTechniques:
  - T1207
query: |
  dsp_parser
  | where EventID == 9212
  | where SecurityIndicatorName == "Evidence of Mimikatz DCShadow attack"
  | 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 == "Evidence of Mimikatz DCShadow attack"

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	`Evidence of Mimikatz DCShadow attack`	`field:"SecurityIndicatorName" kind:eq value:"Evidence of Mimikatz DCShadow attack"`

Output fields

These fields are emitted when the rule matches.

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