7zip_commandline_to_smb_share_path.yml

name: 7zip CommandLine To SMB Share Path
id: 01d29b48-ff6f-11eb-b81e-acde48001122
version: 1
date: '2021-08-17'
author: Teoderick Contreras, Splunk
status: production
type: Hunting
description: This search is to detect a suspicious 7z process with commandline pointing
  to SMB network share. This technique was seen in CONTI LEAK tools where it use 7z
  to archive a sensitive files and place it in network share tmp folder. This search
  is a good hunting query that may give analyst a hint why specific user try to archive
  a file pointing to SMB user which is un usual.
data_source:
- Sysmon Event ID 1
search:
  selection1:
    OriginalFileName: 7z.exe
  selection2:
    Image|endswith:
    - 7z.exe
    - 7za.exe
  selection3:
    OriginalFileName: 7za.exe
  selection4:
    CommandLine:
    - '*\\C$\\*'
    - '*\\Admin$\\*'
    - '*\\IPC$\\*'
  condition: (selection1 or selection2 or selection3) and selection4
how_to_implement: To successfully implement this search, you need to be ingesting
  logs with the process name, parent process, and command-line executions from your
  endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the
  Sysmon TA. Tune and filter known instances where renamed 7z.exe may be used.
known_false_positives: unknown
references:
- https://threadreaderapp.com/thread/1423361119926816776.html
tags:
  analytic_story:
  - Ransomware
  asset_type: Endpoint
  confidence: 50
  impact: 50
  message: archive process $process_name$ with suspicious cmdline $process$ in host
    $dest$
  mitre_attack_id:
  - T1560.001
  - T1560
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: SourceImage
    type: Process
    role:
    - Attacker
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  risk_score: 25
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/conti/conti_leak/windows-sysmon_7z.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog