Detection rules › Splunk

Password Spraying Windows (Windows Event Log)

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

Adversaries may use a single or small list of commonly used passwords against many different accounts to attempt to acquire valid account credentials

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1110.003 Brute Force: Password Spraying

References

Event coverage

Rule body yaml

id: '5847.6115'
title: Password Spraying Windows
description: 'Adversaries may use a single or small list of commonly used passwords
  against many different accounts to attempt to acquire valid account credentials.
  -- Threat Actor Association: Volt Typhoon - Software Association: Conti'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` TERM("4625") | search signature_id=4625|
  table _time, host, user signature_id, user, src_ip | bin span=10s | stats values(*)
  as * by _time, host | eventstats dc(user) as users by _time, host | where users
  > 2 '
techniques:
- credential-access:brute force:password spraying
technique_id:
- T1110.003
data_category:
- Windows event logs
references:
- https://www.cyber.gov.au/acsc/view-all-content/advisories/2019-130-password-spray-attacks-detection-and-mitigation-strategies

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_winevent` TERM("4625")

Stage 2: search

| search signature_id=4625

Stage 3: table

| table _time, host, user signature_id, user, src_ip

Stage 4: bucket

| bin span=10s

Stage 5: stats

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

Stage 6: eventstats

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

Stage 7: where

| where users > 2

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
signature_ideq
  • 4625 corpus 2 (splunk 2)
usersgt
  • 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
1"4625"