Detection rules › Splunk

Driver as Command Parameter (Windows Event Log)

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

Adversaries may use signed drivers in order to take advantage of vulnerabilities in order to execute malicious code or establish persistence. This use case looks for when a driver file (.sys) has been passed as a command line parameter

MITRE ATT&CK coverage

References

Event coverage

Rule body yaml

id: '6129.6614'
title: Driver as Command Parameter
description: 'Adversaries may use signed drivers in order to take advantage of vulnerabilities
  in order to execute malicious code or establish persistence. This use case looks
  for when a driver file (.sys) has been passed as a command line parameter. -- Threat
  Actor Association: Bluebottle, Lancefly, Lazarus - Software Association: Cuba, DirtyMoe,
  HermeticWiper - Atomics T1014 Test #3'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
  "<EventID>4688<" OR Type=Process) "sys" | regex process="(?i)\.sys"| table _time,
  host, user, signature_id, process, process_*, parent_process_* | bin span=1s | stats
  values(*) as * by _time, host '
techniques:
- defense-evasion:system binary proxy execution
- privilege-escalation:exploitation for privilege escalation
technique_id: 
- T1218
- T1068
data_category:
- Windows event logs
- Process command-line parameters
references:
- https://zerosum0x0.blogspot.com/2017/07/puppet-strings-dirty-secret-for-free.html
- http://www.fuzzysecurity.com/tutorials/28.html

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR "<EventID>4688<" OR Type=Process) "sys"

Stage 2: regex

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

Stage 3: table

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

Stage 4: bucket

| bin span=1s

Stage 5: stats

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

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)
processregex_match
  • "(?i).sys"

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>4688<"
1"sys"