Potential Persistence Via App Paths Default Property — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: high. Source dates: 2022-08-10 / 2023-08-17.

{
  "category": "registry_set",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 91b4cac04919d422c334573385b1fb5685d9e2d8dd6f95ea992f0feaf43ee72c

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Potential Persistence Via App Paths Default Property
id: 707e097c-e20f-4f67-8807-1f72ff4500d6
status: test
description: |
    Detects changes to the "Default" property for keys located in the \Software\Microsoft\Windows\CurrentVersion\App Paths\ registry. Which might be used as a method of persistence
    The entries found under App Paths are used primarily for the following purposes.
    First, to map an application's executable file name to that file's fully qualified path.
    Second, to prepend information to the PATH environment variable on a per-application, per-process basis.
references:
    - https://www.hexacorn.com/blog/2013/01/19/beyond-good-ol-run-key-part-3/
    - https://learn.microsoft.com/en-us/windows/win32/shell/app-registration
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-08-10
modified: 2023-08-17
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1546.012
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: '\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths'
        TargetObject|endswith:
            - '(Default)'
            - 'Path'
        Details|contains:
            # Add more suspicious paths or binaries as you see fit.
            - '\Users\Public'
            - '\AppData\Local\Temp\'
            - '\Windows\Temp\'
            - '\Desktop\'
            - '\Downloads\'
            - '%temp%'
            - '%tmp%'
            - 'iex'
            - 'Invoke-'
            - 'rundll32'
            - 'regsvr32'
            - 'mshta'
            - 'cscript'
            - 'wscript'
            - '.bat'
            - '.hta'
            - '.dll'
            - '.ps1'
    condition: selection
falsepositives:
    - Legitimate applications registering their binary from on of the suspicious locations mentioned above (tune it)
level: high

Original YAML and metadata in JSON

False positives

• Legitimate applications registering their binary from on of the suspicious locations mentioned above (tune it)

Source references

• https://www.hexacorn.com/blog/2013/01/19/beyond-good-ol-run-key-part-3/
• https://learn.microsoft.com/en-us/windows/win32/shell/app-registration