Detection rules › Sigma

Potential SNAKE Malware Persistence Service Execution

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

Detects a specific child/parent process relationship indicative of a "WerFault" process running from the "WinSxS" as a service. This could be indicative of potential SNAKE malware activity as reported by CISA.

MITRE ATT&CK coverage

TacticTechniques
ExecutionNo specific technique

Event coverage

Rule body yaml

title: Potential SNAKE Malware Persistence Service Execution
id: f7536642-4a08-4dd9-b6d5-c3286d8975ed
status: test
description: Detects a specific child/parent process relationship indicative of a "WerFault" process running from the "WinSxS" as a service. This could be indicative of potential SNAKE malware activity as reported by CISA.
references:
    - https://media.defense.gov/2023/May/09/2003218554/-1/-1/0/JOINT_CSA_HUNTING_RU_INTEL_SNAKE_MALWARE_20230509.PDF
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-05-04
tags:
    - attack.execution
    - detection.emerging-threats
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\services.exe'
        Image|startswith: 'C:\Windows\WinSxS\'
        Image|endswith: '\WerFault.exe'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    ParentImage|endswith: '\services.exe'
    Image|startswith: 'C:\Windows\WinSxS\'
    Image|endswith: '\WerFault.exe'

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
  • \WerFault.exe corpus 9 (sigma 9)
Imagestarts_with
  • C:\Windows\WinSxS\
ParentImageends_with
  • \services.exe corpus 8 (sigma 8)