Windows Process Access to Uncommon Target Images Using PROCESS_ALL_ACCESS

Alerts on Windows events granting PROCESS_ALL_ACCESS to processes with uncommon target image filenames.

FreeReviewedSigma · Low · v2
Product
windows
Category
process_access
Author
Nasreddine Bencherchali (Nextron Systems), frack113 (SigmaHQ), DRL 1.1
Published
2024-05-27
Updated
2026-07-31
title: Windows Process Access to Uncommon Target Images Using PROCESS_ALL_ACCESS
id: 022b4db6-1993-46c8-a38e-daf1aec436ce
status: test
description: This rule flags process access requests where the target image filename ends with a common user application (e.g., calc.exe, notepad.exe, mspaint.exe) and the granted access mask is PROCESS_ALL_ACCESS. Attackers can use full process rights to inspect, modify, or interfere with another process, which is often leveraged during stealthy privilege escalation or tampering. The detection relies on Windows process-access telemetry that includes the target image path/name and the granted access mask.
references:
  - https://learn.microsoft.com/en-us/windows/win32/procthread/process-security-and-access-rights
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_access/proc_access_win_susp_all_access_uncommon_target.yml
author: Nasreddine Bencherchali (Nextron Systems), frack113, Huntrule Team
date: 2024-05-27
tags:
  - attack.privilege-escalation
  - attack.stealth
  - attack.t1055.011
logsource:
  category: process_access
  product: windows
detection:
  selection:
    TargetImage|endswith:
      - \calc.exe
      - \calculator.exe
      - \mspaint.exe
      - \notepad.exe
      - \ping.exe
      - \wordpad.exe
      - \write.exe
    GrantedAccess: "0x1FFFFF"
  condition: selection
falsepositives:
  - Unknown
level: low
license: DRL-1.1
related:
  - id: a24e5861-c6ca-4fde-a93c-ba9256feddf0
    type: derived