Detection rules › Kusto

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

TacticTechniques
Defense ImpairmentT1207 Rogue Domain Controller

Rule body kusto

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

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.

FieldKindValues
EventIDeq
  • 9212 transforms: cased
SecurityIndicatorNameeq
  • Evidence of Mimikatz DCShadow attack transforms: cased

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.

FieldSource
DnsDomainextend
HostNameextend