Detection rules › Splunk

Certutil Execution (Windows Event Log)

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

certutil is a command-line utility that can be used to obtain certificate authority information and configure Certificate Services. This use case looks for process executions of certutil

MITRE ATT&CK coverage

References

Telemetry coverage

Rule body

id: '6167.6701'
title: Certutil Execution
description: 'certutil is a command-line utility that can be used to obtain certificate
  authority information and configure Certificate Services. This use case looks for
  process executions of certutil. -- Threat Actor Association: DarkSide, BlackMatter,
  REvil - Software Association: HermeticWiper/Trojan.Killdisk -- Living Off the Land
  Binary and Scripts (LOLBAS) (LOLBIN) -- Atomics 1003.002 Test #5 Atomics 1140 Test
  #1'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
  "<EventID>4688<" OR Type=Process) (TERM(certutil) OR "certutil.exe") | table _time,
  host, user, signature_id, process, process_*, parent_* | bin span=1s | stats values(*)
  as * by _time, host | where match(process_name, "(?i)certutil") '
techniques:
- command-and-control:data encoding
- command-and-control:ingress tool transfer
- defense-evasion:deobfuscate/decode files or information
- defense-evasion:obfuscated files or information
technique_id: 
- T1132
- T1105
- T1140
- T1027
data_category:
- Windows event logs
references:
- https://lolbas-project.github.io/lolbas/Binaries/Certutil/
- https://www.fireeye.com/blog/threat-research/2018/09/apt10-targeting-japanese-corporations-using-updated-ttps.html

Stages and Predicates

Stage 1: search

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

Stage 2: table

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

Stage 3: bucket

| bin span=1s

Stage 4: stats

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

Stage 5: where

| where match(process_name, "(?i)certutil")

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
EventCodeeq
  • 4688 corpus 317 (splunk 283, kusto 33, elastic 1)
field:"EventID" kind:eq value:"4688"
process_nameregex_match
  • "(?i)certutil" corpus 4 (splunk 4)
field:"process_name" kind:regex_match

Search terms

These SPL tokens match against raw event text.

StageTerm
1"<EventID>4688<"
1certutil
1"certutil.exe"