Detection rules › Sigma

Suspicious Execution Location Of Wermgr.EXE

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

Detects suspicious Windows Error Reporting manager (wermgr.exe) execution location.

MITRE ATT&CK coverage

TacticTechniques
ExecutionNo specific technique

Event coverage

Rule body yaml

title: Suspicious Execution Location Of Wermgr.EXE
id: 5394fcc7-aeb2-43b5-9a09-cac9fc5edcd5
related:
    - id: 396f6630-f3ac-44e3-bfc8-1b161bc00c4e
      type: similar
status: test
description: Detects suspicious Windows Error Reporting manager (wermgr.exe) execution location.
references:
    - https://www.trendmicro.com/en_us/research/22/j/black-basta-infiltrates-networks-via-qakbot-brute-ratel-and-coba.html
    - https://www.echotrail.io/insights/search/wermgr.exe
    - https://github.com/binderlabs/DirCreate2System
author: Florian Roth (Nextron Systems)
date: 2022-10-14
modified: 2023-08-23
tags:
    - attack.execution
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\wermgr.exe'
    filter_main_legit_location:
        Image|startswith:
            - 'C:\Windows\System32\'
            - 'C:\Windows\SysWOW64\'
            - 'C:\Windows\WinSxS\'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    Image|endswith: '\wermgr.exe'

Stage 2: not filter_main_legit_location

filter_main_legit_location:
    Image|startswith:
        - 'C:\Windows\System32\'
        - 'C:\Windows\SysWOW64\'
        - 'C:\Windows\WinSxS\'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
Imagestarts_withC:\Windows\SysWOW64\
Imagestarts_withC:\Windows\System32\
Imagestarts_withC:\Windows\WinSxS\

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Imageends_with
  • \wermgr.exe corpus 5 (sigma 5)