Potential Persistence Via Microsoft Compatibility Appraiser

Status: test
Severity: medium
Log source: category process_creation, product windows
Author: Sreeman
Source: github.com/SigmaHQ/sigma

Detects manual execution of the "Microsoft Compatibility Appraiser" task via schtasks. In order to trigger persistence stored in the "\AppCompatFlags\TelemetryController" registry key.

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1053.005` Scheduled Task/Job: Scheduled Task
Persistence	`T1053.005` Scheduled Task/Job: Scheduled Task
Privilege Escalation	`T1053.005` Scheduled Task/Job: Scheduled Task

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation

Rule body

title: Potential Persistence Via Microsoft Compatibility Appraiser
id: f548a603-c9f2-4c89-b511-b089f7e94549
related:
    - id: 73a883d0-0348-4be4-a8d8-51031c2564f8
      type: derived
status: test
description: |
    Detects manual execution of the "Microsoft Compatibility Appraiser" task via schtasks.
    In order to trigger persistence stored in the "\AppCompatFlags\TelemetryController" registry key.
references:
    - https://www.trustedsec.com/blog/abusing-windows-telemetry-for-persistence/
author: Sreeman
date: 2020-09-29
modified: 2023-02-10
tags:
    - attack.privilege-escalation
    - attack.execution
    - attack.persistence
    - attack.t1053.005
logsource:
    product: windows
    category: process_creation
detection:
    selection_img:
        - Image|endswith: '\schtasks.exe'
        - OriginalFileName: 'schtasks.exe'
    selection_cli:
        CommandLine|contains|all:
            - 'run '
            - '\Application Experience\Microsoft Compatibility Appraiser'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: `condition`

all of selection_*

Stage 1: `selection_img`

selection_img:
    - Image|endswith: '\schtasks.exe'
    - OriginalFileName: 'schtasks.exe'

Stage 2: `selection_cli`

selection_cli:
    CommandLine|contains|all:
        - 'run '
        - '\Application Experience\Microsoft Compatibility Appraiser'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`\Application Experience\Microsoft Compatibility Appraiser` `run`	`field:"CommandLine" kind:match`
`Image`	ends_with	`\schtasks.exe` corpus 55 (sigma 55)	`field:"Image" kind:ends_with value:"\schtasks.exe"`
`OriginalFileName`	eq	`schtasks.exe` corpus 31 (sigma 18, elastic 9, splunk 4)	`field:"OriginalFileName" kind:eq value:"schtasks.exe"`