Detection rules › Splunk

User_Domain Enumeration Tool - Windows (PowerShell)

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

Adversaries may attempt to get a listing of domain accounts. This information can help adversaries determine which domain accounts exist to aid in follow-on behavior. This use case detects the execution of ADSISearcher or ADFind or parameters filtering for user or domain enumeration

MITRE ATT&CK coverage

References

Telemetry coverage

Rule body

id: '17165.27786'
title: User_Domain Enumeration Tool - Windows
description: 'Adversaries may attempt to get a listing of domain accounts. This information
  can help adversaries determine which domain accounts exist to aid in follow-on behavior.
  This use case detects the execution of ADSISearcher or ADFind or parameters filtering
  for user or domain enumeration. -- Threat Actor Association: Alloy Taurus/Gallium
  -- Atomics T1087.002 Test #7 Atomics T1087.002 Test #12 Atomics T1087.002 Test #13
  Atomics T1087.002 Test #14 Atomics T1087.002 Test #16'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4103) OR
  "<EventID>4103<" OR TERM(EventCode=4104) OR "<EventID>4104<") (TERM(adsisearcher)
  OR "adsisearcher") OR (TERM(adfind) OR "adfind") OR (TERM(kerbrute) OR "kerbrute")
  ("searchroot" OR "objectcategory=" OR "userenum") | regex process="(?i)searchroot|objectcategory=|userenum"
  | table _time, host, user, user, process | bin span=1s | stats values(*) as * by
  _time, host '
techniques:
- discovery:account discovery:domain account
- discovery:account discovery
- persistence:create account:domain account
technique_id:
- T1087.002
- T1136.002
data_category:
- PowerShell logs
references:
- https://devblogs.microsoft.com/scripting/use-the-powershell-adsisearcher-type-accelerator-to-search-active-directory/

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4103) OR "<EventID>4103<" OR TERM(EventCode=4104) OR "<EventID>4104<") (TERM(adsisearcher) OR "adsisearcher") OR (TERM(adfind) OR "adfind") OR (TERM(kerbrute) OR "kerbrute") ("searchroot" OR "objectcategory=" OR "userenum")

Stage 2: regex

| regex process="(?i)searchroot|objectcategory=|userenum"

Stage 3: table

| table _time, host, user, user, process

Stage 4: bucket

| bin span=1s

Stage 5: stats

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

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
EventCodeeq
  • 4103 corpus 105 (splunk 105)
  • 4104 corpus 269 (splunk 269)
field:"EventID" kind:eq
processregex_match
    • "(?i)searchroot
    • objectcategory=
    • userenum"
    corpus 3 (splunk 3)
field:"CommandLine" kind:regex_match

Search terms

These SPL tokens match against raw event text.

StageTerm
1"<EventID>4103<"
1"<EventID>4104<"
1adsisearcher
1"adsisearcher"
1adfind
1"adfind"
1kerbrute
1"kerbrute"
1"searchroot"
1"objectcategory="
1"userenum"