Detection rules › Sigma

Remote shell execution via SMB admin share

Status
experimental
Severity
high
Log source
product windows, service security
Author
mdecrevoisier
Source
github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker execute a remote shell via the admin share.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Remote shell execution via SMB admin share
description: Detects scenarios where an attacker execute a remote shell via the admin share.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0008-Lateral%20Movement/T1021.002%20-SMB%20Windows%20Admin%20Shares
- https://www.offensive-security.com/metasploit-unleashed/psexec-pass-hash/
tags:
- attack.lateral_movement
- attack.t1021.002
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID: 5145
    ShareName: '\\*\ADMIN$'
    RelativeTargetName|endswith:
      - \cmd.exe
      - \powershell.exe
      - \pwsh.exe # PowerShell v6
  condition: selection
falsepositives:
- Administrator activity
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  EventID: 5145
  ShareName: '\\*\ADMIN$'
  RelativeTargetName|endswith:
    - \cmd.exe
    - \powershell.exe
    - \pwsh.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
RelativeTargetNameends_with
  • \cmd.exe
  • \powershell.exe
  • \pwsh.exe
ShareNamewildcard
  • \\*\ADMIN$ corpus 6 (sigma 6)