Detection rules › Splunk

Dump File Identified (PowerShell)

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

Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password, from the operating system and software. This use case looks command line arguments that include a ".dmp" file, which may indicate a dump has teken place or that a dmp file is being analyzed locally

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1003 OS Credential Dumping

References

Event coverage

Rule body yaml

id: '6003.6383'
title: Dump File Identified
description: 'Adversaries may attempt to dump credentials to obtain account login
  and credential material, normally in the form of a hash or a clear text password,
  from the operating system and software. This use case looks command line arguments
  that include a ".dmp" file, which may indicate a dump has teken place or that a
  dmp file is being analyzed locally. -- Threat Actor Association: Cadet Blizzard,
  Redfly - Software Association: Akira, Black Basta, LockBit, Quantum, Rhysida, Vice
  Society'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4103) OR
  TERM(EventCode=4104)) TERM(dmp) | regex process="(?i)\.dmp" | rex field=process
  "(?<file>(?i)\S+\.dmp") | table _time, host, user process, process_*, signature_id,
  file | bin span=1s | stats values(*) as * by _time, host | where isnotnull(file) '
techniques:
- credential-access:os credential dumping
technique_id: 
- T1003
data_category:
- PowerShell logs
- Process command-line parameters
references:
- https://www.ired.team/offensive-security/credential-access-and-credential-dumping/dumping-lsass-passwords-without-mimikatz-minidumpwritedump-av-signature-bypass

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4103) OR TERM(EventCode=4104)) TERM(dmp)

Stage 2: regex

| regex process="(?i)\.dmp"

Stage 3: eval

| rex field=process "(?<file>(?i)\S+\.dmp")

Stage 4: table

| table _time, host, user process, process_*, signature_id, file

Stage 5: bucket

| bin span=1s

Stage 6: stats

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

Stage 7: where

| where isnotnull(file)

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
  • 4103 corpus 105 (splunk 105)
  • 4104 corpus 268 (splunk 268)
fileis_not_null
  • (no value, null check)
processregex_match
  • "(?i).dmp" 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
1TERM
1dmp