Detection rules › Splunk

Esentutl Execution (Windows Event Log)

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

Esentutl is a command-line tool that provides database utilities for the Windows Extensible Storage Engine. This use case looks for esentutl execution or from an executable running common process command line switches used by adversaries

MITRE ATT&CK coverage

References

Telemetry coverage

Rule body

id: '6147.6666'
title: Esentutl Execution
description: 'Esentutl is a command-line tool that provides database utilities for
  the Windows Extensible Storage Engine. This use case looks for esentutl execution
  or from an executable running common process command line switches used by adversaries.
  Living Off the Land Binary and Scripts (LOLBAS) (LOLBIN) Threat Actor Association:
  Wizard Spider Software Association: Bazar, Conti, Trickbot Atomics T1003.002 Test
  #3'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
  "<EventID>4688<" OR Type=Process) ( "esentutl.exe" OR (".exe" "/y" "/d") OR "esentutl"
  ) | regex process="(?i)(esentutl|\.exe)\"?\s.*\/y\s.*\/d\s" | table _time, host,
  user, signature_id, process, process_*, parent_* | bin span=1s | stats values(*)
  as * by _time, host '
techniques:
- command-and-control:ingress tool transfer
- credential-access:os credential dumping:security account manager
- credential-access:os credential dumping:ntds
- lateral-movement:lateral tool transfer
- defense-evasion:hide artifacts
technique_id:
- T1105
- T1003.002
- T1003.003
- T1570
- T1564
data_category:
- Windows event logs
- Process command-line parameters
references:
- 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) ( "esentutl.exe" OR (".exe" "/y" "/d") OR "esentutl" )

Stage 2: regex

| regex process="(?i)(esentutl|\.exe)\"?\s.*\/y\s.*\/d\s"

Stage 3: table

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

Stage 4: bucket

| bin span=1s

Stage 5: stats

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

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"
processregex_match
  • "(?i)(esentutl|.exe)\"?\s.*\/y\s.*\/d\s" corpus 2 (splunk 2)
field:"CommandLine" kind:regex_match

Search terms

These SPL tokens match against raw event text.

StageTerm
1"<EventID>4688<"
1"esentutl.exe"
1".exe"
1"/y"
1"/d"
1"esentutl"