New Application in AppCompat

Hunt Hypothesis

A General detection for a new application in AppCompat. This indicates an application executing for the first time on an endpoint.

Detection Rule

Sigma (Original)

title: New Application in AppCompat
id: 60936b49-fca0-4f32-993d-7415edcf9a5d
status: test
description: A General detection for a new application in AppCompat. This indicates an application executing for the first time on an endpoint.
references:
    - https://github.com/OTRF/detection-hackathon-apt29/issues/1
    - https://github.com/OTRF/ThreatHunter-Playbook/blob/2d4257f630f4c9770f78d0c1df059f891ffc3fec/docs/evals/apt29/detections/1.A.1_DFD6A782-9BDB-4550-AB6B-525E825B095E.md
author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)
date: 2020-05-02
modified: 2023-08-17
tags:
    - attack.execution
    - attack.t1204.002
logsource:
    product: windows
    category: registry_set
detection:
    selection:
        TargetObject|contains: '\AppCompatFlags\Compatibility Assistant\Store\'
    condition: selection
falsepositives:
    - This rule is to explore new applications on an endpoint. False positives depends on the organization.
    - Newly setup system.
    - Legitimate installation of new application.
level: informational

KQL (Azure Sentinel)

imRegistry
| where RegistryKey endswith "\\AppCompatFlags\\Compatibility Assistant\\Store*"

KQL (Microsoft 365 Defender)

DeviceRegistryEvents
| where RegistryKey endswith "\\AppCompatFlags\\Compatibility Assistant\\Store*"

Required Data Sources

False Positive Guidance

• This rule is to explore new applications on an endpoint. False positives depends on the organization.
• Newly setup system.
• Legitimate installation of new application.

MITRE ATT&CK Context

• Tactic: Execution
• Technique: T1204.002 — T1204.002

References

• https://github.com/OTRF/detection-hackathon-apt29/issues/1
• https://github.com/OTRF/ThreatHunter-Playbook/blob/2d4257f630f4c9770f78d0c1df059f891ffc3fec/docs/evals/apt29/detections/1.A.1_DFD6A782-9BDB-4550-AB6B-525E825B095E.md
• SigmaHQ Rule