Detection rules › Sigma

Impacket WMIexec 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 attempts to remotely execute WMIexec via SMB admin share in order to escalate privileges.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Impacket WMIexec execution via SMB admin share
description: Detects scenarios where an attacker attempts to remotely execute WMIexec via SMB admin share in order to escalate privileges. 
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0008-Lateral%20Movement/T1021.002%20-SMB%20Windows%20Admin%20Shares
- https://riccardoancarani.github.io/2020-05-10-hunting-for-impacket/#wmiexecpy
- https://www.darkoperator.com/blog/2017/10/14/basics-of-tracking-wmi-activity
- https://www.crowdstrike.com/blog/how-to-detect-and-prevent-impackets-wmiexec/
- https://www.microsoft.com/en-us/security/blog/2022/10/18/defenders-beware-a-case-for-post-ransomware-investigations/
tags:
- attack.lateral_movement
- attack.t1021.002
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID: 5145
    ShareName: '\\*\ADMIN$'
    RelativeTargetName|re: '__\d*\.\d*' # example: '__1619091076.1269338'. Can be changed in source code
  condition: selection
falsepositives:
- None
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  EventID: 5145
  ShareName: '\\*\ADMIN$'
  RelativeTargetName|re: '__\d*\.\d*'

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
RelativeTargetNameregex_match
  • __\d*.\d*
ShareNamewildcard
  • \\*\ADMIN$ corpus 6 (sigma 6)