Detection rules › Kusto

CyberArkEPM - Renamed Windows binary

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

'Detects renamed windows binaries.'

MITRE ATT&CK coverage

TacticTechniques
ExecutionT1204 User Execution
StealthT1036 Masquerading

Rule body kusto

id: 9281b7cc-8f05-45a9-bf10-17fb29492a84
name: CyberArkEPM - Renamed Windows binary
description: |
  'Detects renamed windows binaries.'
severity: High
requiredDataConnectors:
  - connectorId: CyberArkEPM
    dataTypes:
      - CyberArkEPM
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Execution
  - DefenseEvasion
relevantTechniques:
  - T1204
  - T1036
query: | 
  CyberArkEPM
  | where EventSubType != 'AttackAttempt'
  | where ActingProcessName has @'\'
  | where ActingProcessName !has ActingProcessFileInternalName
  | project EventEndTime, EventMessage, ActorUsername, ActingProcessFileInternalName
  | extend AccountCustomEntity = ActorUsername
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountCustomEntity
version: 1.0.0
kind: Scheduled

Stages and Predicates

Stage 1: source

CyberArkEPM

Stage 2: where

| where EventSubType != 'AttackAttempt'

Stage 3: where

| where ActingProcessName has @'\'

Stage 4: where

| where ActingProcessName !has ActingProcessFileInternalName

Stage 5: project

| project EventEndTime, EventMessage, ActorUsername, ActingProcessFileInternalName

Stage 6: extend

| extend AccountCustomEntity = ActorUsername

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
ActingProcessNamematchActingProcessFileInternalName

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
ActingProcessNamematch
  • \ transforms: term
EventSubTypene
  • AttackAttempt 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
ActingProcessFileInternalNameproject
ActorUsernameproject
EventEndTimeproject
EventMessageproject
AccountCustomEntityextend