Suspicious Service Installed — Sigma Rule

Rule metadata and linked tags

Author: xknow (@xknow_infosec), xorxes (@xor_xes). Source status: test; severity: medium. Source dates: 2019-04-08 / 2023-08-17.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 90309a211bab99584313a14d64699dc23a0be6767b4273b808ac2d310aefdcd8

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: Suspicious Service Installed
id: f2485272-a156-4773-82d7-1d178bc4905b
status: test
description: |
  Detects installation of NalDrv or PROCEXP152 services via registry-keys to non-system32 folders.
  Both services are used in the tool Ghost-In-The-Logs (https://github.com/bats3c/Ghost-In-The-Logs), which uses KDU (https://github.com/hfiref0x/KDU)
references:
    - https://web.archive.org/web/20200419024230/https://blog.dylan.codes/evading-sysmon-and-windows-event-logging/
author: xknow (@xknow_infosec), xorxes (@xor_xes)
date: 2019-04-08
modified: 2023-08-17
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject:
            - 'HKLM\System\CurrentControlSet\Services\NalDrv\ImagePath'
            - 'HKLM\System\CurrentControlSet\Services\PROCEXP152\ImagePath'
    filter:
        Image|endswith:
            # Please add the full paths that you use in your environment to tighten the rule
            - '\procexp64.exe'
            - '\procexp.exe'
            - '\procmon64.exe'
            - '\procmon.exe'
            - '\handle.exe'
            - '\handle64.exe'
        Details|contains: '\WINDOWS\system32\Drivers\PROCEXP152.SYS'
    condition: selection and not filter
falsepositives:
    - Other legimate tools using this service names and drivers. Note - clever attackers may easily bypass this detection by just renaming the services. Therefore just Medium-level and don't rely on it.
level: medium

Original YAML and metadata in JSON

False positives

• Other legimate tools using this service names and drivers. Note - clever attackers may easily bypass this detection by just renaming the services. Therefore just Medium-level and don't rely on it.

Source references

• https://web.archive.org/web/20200419024230/https://blog.dylan.codes/evading-sysmon-and-windows-event-logging/