Detection rules › Sigma

New Process Created Via Taskmgr.EXE

Status
test
Severity
low
Log source
category process_creation, product windows
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the creation of a process via the Windows task manager. This might be an attempt to bypass UAC

Known false positives

  • Administrative activity

MITRE ATT&CK coverage

TacticTechniques
Stealth

Telemetry coverage

Rule body

title: New Process Created Via Taskmgr.EXE
id: 3d7679bd-0c00-440c-97b0-3f204273e6c7
status: test
description: Detects the creation of a process via the Windows task manager. This might be an attempt to bypass UAC
references:
    - https://twitter.com/ReneFreingruber/status/1172244989335810049
author: Florian Roth (Nextron Systems)
date: 2018-03-13
modified: 2024-01-18
tags:
    - attack.stealth
    - attack.t1036
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\taskmgr.exe'
    filter_main_generic:
        Image|endswith:
            - ':\Windows\System32\mmc.exe'
            - ':\Windows\System32\resmon.exe'
            - ':\Windows\System32\Taskmgr.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Administrative activity
level: low

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    ParentImage|endswith: '\taskmgr.exe'

Stage 2: not filter_main_generic

filter_main_generic:
    Image|endswith:
        - ':\Windows\System32\mmc.exe'
        - ':\Windows\System32\resmon.exe'
        - ':\Windows\System32\Taskmgr.exe'

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
Imageends_with:\Windows\System32\Taskmgr.exeexcludes:Image field:"Image" value:":\Windows\System32\Taskmgr.exe"
Imageends_with:\Windows\System32\mmc.exeexcludes:Image field:"Image" value:":\Windows\System32\mmc.exe"
Imageends_with:\Windows\System32\resmon.exeexcludes:Image field:"Image" value:":\Windows\System32\resmon.exe"

Indicators

These rows show field, operator, and value matches.