Uncommon Sigverif.EXE Child Process

Status: test
Severity: medium
Log source: category process_creation, product windows
Author: Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects uncommon child processes spawning from "sigverif.exe", which could indicate potential abuse of the latter as a living of the land binary in order to proxy execution.

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1216` System Script Proxy Execution

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation
Security-Auditing	Event ID 4688: A new process has been created.

Rule body

title: Uncommon Sigverif.EXE Child Process
id: 7d4aaec2-08ed-4430-8b96-28420e030e04
status: test
description: |
    Detects uncommon child processes spawning from "sigverif.exe", which could indicate potential abuse of the latter as a living of the land binary in order to proxy execution.
references:
    - https://www.hexacorn.com/blog/2018/04/27/i-shot-the-sigverif-exe-the-gui-based-lolbin/
    - https://twitter.com/0gtweet/status/1457676633809330184
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-08-19
modified: 2024-08-27
tags:
    - attack.stealth
    - attack.t1216
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\sigverif.exe'
    filter_main_werfault:
        Image:
            - 'C:\Windows\System32\WerFault.exe'
            - 'C:\Windows\SysWOW64\WerFault.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: `condition`

selection and not 1 of filter_main_*

Stage 1: `selection`

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

Stage 2: `not filter_main_werfault`

filter_main_werfault:
    Image:
        - 'C:\Windows\System32\WerFault.exe'
        - 'C:\Windows\SysWOW64\WerFault.exe'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`Image`	eq	`C:\Windows\SysWOW64\WerFault.exe`	`excludes:Image` `field:"Image" value:"C:\Windows\SysWOW64\WerFault.exe"`
`Image`	eq	`C:\Windows\System32\WerFault.exe`	`excludes:Image` `field:"Image" value:"C:\Windows\System32\WerFault.exe"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`ParentImage`	ends_with	`\sigverif.exe`	`field:"ParentImage" kind:ends_with value:"\sigverif.exe"`