Detection rules › Splunk
Executable Create Script Process (Sysmon)
A BAT file is a DOS batch file used to execute commands with the Windows Command Prompt (cmd.exe), this usecase will detect common scripting type like bat, sh, and ps1 with an executable parent
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1059.003 Command and Scripting Interpreter: Windows Command Shell |
| Collection | T1119 Automated Collection |
| Exfiltration | T1020 Automated Exfiltration |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
Rule body yaml
id: '1116.1192'
title: Executable Create Script Process
description: 'A BAT file is a DOS batch file used to execute commands with the Windows
Command Prompt (cmd.exe), this usecase will detect common scripting type like bat,
sh, and ps1 with an executable parent. -- Threat Actor Association: APT28 (aka.Fancy
Bear, Fighting Ursa, Forest Blizzard, Pawn Storm, TA422, STRONTIUM), APT29/Nobelium/Cozy
Bear, APT31, APT35/Phosphorus/Magic Hound, APT41, APT43, Blind Eagle/APT-C-36, FIN8,
Gamaredon Group/Shuckworm, GoldenJackal, Karakurt, Mustang Panda (aka. Stately Taurus//Earth
Preta/BRONZE PRESIDENT/TA416/RedDelta), Redfly, TA413, UAC-0057 (GhostWriter), Vice
Society, Volt Typhoon, Winter Vivern, Witchetty, Wizard Spider -- Software Association:
ALPHV/BlackCat, AvosLocker, Bazarloader, BianLian, Black Basta, Blackbyte, Clop,
Conti, Dharma, Emotet, Hive, LV, Prestige, PYSA/Mespinoza, Quantum, Rhysida, Royal,
Snatch, Vice Society, TargetCompany, Trigona, XingLocker, Zloader - Atomics T1547.001
Test#6 - #TrendingThreat #Russia #Ukraine'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` EventCode=1 (TERM("exe") AND
(TERM(".bat") OR TERM(".ps1") OR TERM(".sh"))) | regex process_name="(?i)\w+\.(exe)"|
regex process="(?i)\w+\.(bat|ps1|sh)" | table _time, host, user, signature_id, dest_port,
process, process_name, parent_process_name, parent_process | bin span=1s | stats
values(*) as * by _time, host, process | eventstats c(process) as c_process | where
c_process<10 '
techniques:
- execution:command and scripting interpreter
- exfiltration:automated exfiltration
- execution:command and scripting interpreter:windows command shell
- collection:automated collection
technique_id:
- T1059
- T1020
- T1059.003
- T1119
data_category:
- Windows Sysmon
references:
- https://www.fireeye.com/blog/threat-research/2016/05/targeted_attacksaga.html
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_sysmon` EventCode=1 (TERM("exe") AND (TERM(".bat") OR TERM(".ps1") OR TERM(".sh")))
Stage 2: regex
| regex process_name="(?i)\w+\.(exe)"
Stage 3: regex
| regex process="(?i)\w+\.(bat|ps1|sh)"
Stage 4: table
| table _time, host, user, signature_id, dest_port, process, process_name, parent_process_name, parent_process
Stage 5: bucket
| bin span=1s
Stage 6: stats
| stats values(*) as * by _time, host, process
Stage 7: eventstats
| eventstats c(process) as c_process
Stage 8: where
| where c_process<10
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.
| Field | Kind | Values |
|---|---|---|
EventCode | eq |
|
c_process | lt |
|
process | regex_match |
|
process_name | regex_match |
|
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.
| Stage | Term |
|---|---|
| 1 | "exe" |
| 1 | ".bat" |
| 1 | ".ps1" |
| 1 | ".sh" |