Detection rules › Splunk

Multiple Host logons (Windows Event Log)

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

Use case looks for users who have logged into multiple hosts

MITRE ATT&CK coverage

TacticTechniques
Initial AccessT1078 Valid Accounts
PersistenceT1078 Valid Accounts
Privilege EscalationT1078 Valid Accounts
StealthT1078 Valid Accounts

References

Event coverage

Rule body yaml

id: '5697.5959'
title: Multiple Host logons
description: 'Use case looks for users who have logged into multiple hosts. -- Threat
  Actor Association: CL-STA-0043'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4624) OR
  "<EventID>4624<") | regex user!="(?i)system|ANONYMOUS\sLOGON|DefaultAppPool|IUSR|(LOCAL|network)\sSERVICE|\$$"
  | table _time, host, user, process, process_*, parent_* | bin span=86400s | stats
  values(*) as * by _time, user | eventstats dc(host) as dc_host by user, _time |
  where dc_host > 2 '
techniques:
- defense-evasion:valid accounts
technique_id: 
- T1078
data_category:
- Windows event logs
references:
- https://www.cadosecurity.com/post/responding-to-solarigate

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4624) OR "<EventID>4624<")

Stage 2: regex

| regex user!="(?i)system|ANONYMOUS\sLOGON|DefaultAppPool|IUSR|(LOCAL|network)\sSERVICE|\$$"

Stage 3: table

| table _time, host, user, process, process_*, parent_*

Stage 4: bucket

| bin span=86400s

Stage 5: stats

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

Stage 6: eventstats

| eventstats dc(host) as dc_host by user, _time

Stage 7: where

| where dc_host > 2

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
userregex_match"(?i)system, ANONYMOUS\sLOGON, DefaultAppPool, IUSR, (LOCAL|network)\sSERVICE, $$"

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
  • 4624 corpus 25 (splunk 13, kusto 8, chronicle 4)
dc_hostgt
  • 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
1"<EventID>4624<"