Suspicious PROCEXP152.sys File Created In TMP — Sigma Rule

Rule metadata and linked tags

Author: xknow (@xknow_infosec), xorxes (@xor_xes). Source status: test; severity: medium. Source dates: 2019-04-08 / 2022-11-22.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: b61a46ad054017ec229e36255a1feb4afacc9f8e6167aaa001410cba0603f73b

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 PROCEXP152.sys File Created In TMP
id: 3da70954-0f2c-4103-adff-b7440368f50e
status: test
description: |
  Detects the creation of the PROCEXP152.sys file in the application-data local temporary folder.
  This driver is used by Sysinternals Process Explorer but also by KDU (https://github.com/hfiref0x/KDU) or Ghost-In-The-Logs (https://github.com/bats3c/Ghost-In-The-Logs), which uses KDU.
references:
    - https://web.archive.org/web/20230331181619/https://blog.dylan.codes/evading-sysmon-and-windows-event-logging/
author: xknow (@xknow_infosec), xorxes (@xor_xes)
date: 2019-04-08
modified: 2022-11-22
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    product: windows
    category: file_event
detection:
    selection:
        TargetFilename|contains: '\AppData\Local\Temp\'
        TargetFilename|endswith: 'PROCEXP152.sys'
    filter:
        Image|contains:
            - '\procexp64.exe'
            - '\procexp.exe'
            - '\procmon64.exe'
            - '\procmon.exe'
    condition: selection and not filter
falsepositives:
    - Other legimate tools using this driver and filename (like Sysinternals). Note - Clever attackers may easily bypass this detection by just renaming the driver filename. 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 driver and filename (like Sysinternals). Note - Clever attackers may easily bypass this detection by just renaming the driver filename. Therefore just Medium-level and don't rely on it.

Source references

• https://web.archive.org/web/20230331181619/https://blog.dylan.codes/evading-sysmon-and-windows-event-logging/