Cab File Extraction Via Wusa.EXE From Potentially Suspicious Paths

Hunt Hypothesis

Detects the execution of the “wusa.exe” (Windows Update Standalone Installer) utility to extract “.cab” files using the “/extract” argument from potentially suspicious paths.

Detection Rule

Sigma (Original)

title: Cab File Extraction Via Wusa.EXE From Potentially Suspicious Paths
id: c74c0390-3e20-41fd-a69a-128f0275a5ea
related:
    - id: 59b39960-5f9d-4a49-9cef-1e4d2c1d0cb9
      type: derived
status: test
description: |
    Detects the execution of the "wusa.exe" (Windows Update Standalone Installer) utility to extract ".cab" files using the "/extract" argument from potentially suspicious paths.
references:
    - https://web.archive.org/web/20180331144337/https://www.fireeye.com/blog/threat-research/2018/03/sanny-malware-delivery-method-updated-in-recently-observed-attacks.html
    - https://www.echotrail.io/insights/search/wusa.exe/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-08-05
modified: 2023-11-28
tags:
    - attack.execution
logsource:
    category: process_creation
    product: windows
detection:
    selection_root:
        Image|endswith: '\wusa.exe'
        CommandLine|contains: '/extract:'
    selection_paths:
        CommandLine|contains:
            - ':\PerfLogs\'
            - ':\Users\Public\'
            - ':\Windows\Temp\'
            - '\Appdata\Local\Temp\'
            # - '\Desktop\'
            # - '\Downloads\'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

KQL (Azure Sentinel)

imProcessCreate
| where (TargetProcessName endswith "\\wusa.exe" and TargetProcessCommandLine contains "/extract:") and (TargetProcessCommandLine contains ":\\PerfLogs\\" or TargetProcessCommandLine contains ":\\Users\\Public\\" or TargetProcessCommandLine contains ":\\Windows\\Temp\\" or TargetProcessCommandLine contains "\\Appdata\\Local\\Temp\\")

Required Data Sources

False Positive Guidance

• Unknown

MITRE ATT&CK Context

• Tactic: Execution

References

• https://web.archive.org/web/20180331144337/https://www.fireeye.com/blog/threat-research/2018/03/sanny-malware-delivery-method-updated-in-recently-observed-attacks.html
• https://www.echotrail.io/insights/search/wusa.exe/
• SigmaHQ Rule