Detection rules › Kusto

Detecting UAC bypass - elevated COM interface

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

This query identifies processes spawned with high integrity from dllhost.exe with a command line that contains one of three specific CLSID GUIDs.

MITRE ATT&CK coverage

TacticTechniques
ImpactT1490 Inhibit System Recovery

Event coverage

Rule body kusto

id: 2d5efc71-2e91-4ca2-8506-857eecb453ec
name: Detecting UAC bypass - elevated COM interface
description: |
  This query identifies processes spawned with high integrity from dllhost.exe with a command line that contains one of three specific CLSID GUIDs.
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: MicrosoftThreatProtection
    dataTypes:
      - DeviceProcessEvents
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Impact
relevantTechniques:
  - T1490
query: |
  DeviceProcessEvents
  | where InitiatingProcessFileName =~ "dllhost.exe"
  | where ProcessIntegrityLevel == "High"
  | where InitiatingProcessCommandLine has_any ("E9495B87-D950-4AB5-87A5-FF6D70BF3E90", "3E5FC7F9-9A51-4367-9063-A120244FBEC7", "D2E7041B-2927-42fb-8E9F-7CE93B6DC937")
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: DeviceName
  - entityType: Account
    fieldMappings:
      - identifier: Sid
        columnName: AccountSid
      - identifier: Name
        columnName: AccountName
      - identifier: NTDomain
        columnName: AccountDomain
  - entityType: Process
    fieldMappings:
      - identifier: CommandLine
        columnName: ProcessCommandLine
version: 1.0.0
kind: Scheduled

Stages and Predicates

Stage 1: source

DeviceProcessEvents

Stage 2: where

| where InitiatingProcessFileName =~ "dllhost.exe"

Stage 3: where

| where ProcessIntegrityLevel == "High"

Stage 4: where

| where InitiatingProcessCommandLine has_any ("E9495B87-D950-4AB5-87A5-FF6D70BF3E90", "3E5FC7F9-9A51-4367-9063-A120244FBEC7", "D2E7041B-2927-42fb-8E9F-7CE93B6DC937")

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
InitiatingProcessCommandLinematch
  • 3E5FC7F9-9A51-4367-9063-A120244FBEC7
  • D2E7041B-2927-42fb-8E9F-7CE93B6DC937
  • E9495B87-D950-4AB5-87A5-FF6D70BF3E90
InitiatingProcessFileNameeq
  • dllhost.exe corpus 7 (elastic 4, kusto 2, splunk 1)
ProcessIntegrityLeveleq
  • High transforms: cased corpus 21 (sigma 17, kusto 3, splunk 1)