Detection rules › Splunk

Impacket_Empire's WMIExec (Windows Event Log)

Group by
_time, host
Source
github.com/anvilogic-forge/armory

Impackets wmiexec.py enables users to execute commands or gain an interactive shell on a remote host

MITRE ATT&CK coverage

References

Event coverage

Rule body yaml

id: '5370.5481'
title: Impacket_Empire's WMIExec
description: 'Impackets wmiexec.py enables users to execute commands or gain an interactive
  shell on a remote host. -- Threat Actor Association: APT28 (aka.Fancy Bear, Fighting
  Ursa, Forest Blizzard, Pawn Storm, TA422, STRONTIUM), APT35/Phosphorus/Magic Hound,
  Cadet Blizzard, FIN8, Stonefly, UNC5221, UTA0178, Volt Typhoon - Software Association:
  ALPHV/Blackcat, BadHatch, Play, LockBit, Prestige, PYSA/Mespinoza, Vice Society'
logic_format: Splunk
logic: ' `get_endpoint_data` `get_endpoint_data_winevent` TERM(EventCode=4688) AND
  (TERM(powershell.exe) OR TERM(cmd.exe)) AND "NT AUTHORITY\\NETWORK SERVICE" | table
  _time, host, user parent_process_id, parent_process_name, parent_process_path, process,
  process_id, process_name | bin span=1s | stats values(*) as * by _time, host | where
  match(process,"(?i)powershell\.exe") OR match(process,"(i?)cmd\.exe") '
techniques:
- execution:command and scripting interpreter:powershell
- execution:windows management instrumentation
technique_id:
- T1059.001
- T1047
data_category:
- Windows event logs
references:
- https://github.com/SecureAuthCorp/impacket/blob/master/examples/wmiexec.py

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_winevent` TERM(EventCode=4688) AND (TERM(powershell.exe) OR TERM(cmd.exe)) AND "NT AUTHORITY\\NETWORK SERVICE"

Stage 2: table

| table _time, host, user parent_process_id, parent_process_name, parent_process_path, process, process_id, process_name

Stage 3: bucket

| bin span=1s

Stage 4: stats

| stats values(*) as * by _time, host

Stage 5: where

| where match(process,"(?i)powershell\.exe") OR match(process,"(i?)cmd\.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
EventCodeeq
  • 4688 corpus 313 (splunk 283, kusto 30)
processmatch
  • "(?i)powershell\.exe" corpus 2 (splunk 2)
  • "(i?)cmd\.exe" corpus 2 (splunk 2)

Search terms

Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.

StageTerm
1TERM
1TERM
1powershell.exe
1TERM
1cmd.exe
1"NT AUTHORITY\\NETWORK SERVICE"