Detection rules › Splunk

Wscript_Cscript Execution (Sysmon)

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

Monitor the execution of wscript or cscript processes as these are commonly utilized by threat actors to run malicious VBScript or JScript code

MITRE ATT&CK coverage

References

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

id: '1029.1033'
title: Wscript_Cscript Execution
description: 'Monitor the execution of wscript or cscript processes as these are commonly
  utilized by threat actors to run malicious VBScript or JScript code Threat Actor
  Association: Actinium/Gamaredon/Primitive Bear, Andariel, Antlion, APT10/menuPass,
  APT28/Fancy Bear, APT29/Nobelium/Cozy Bear, APT31, APT33, APT35, APT37/Chinotto,
  APT43, Blind Eagle/APT-C-36, Carbanak, Evilnum, FIN7, Gamaredon Group/Shuckworm,
  Kimsuky, Mustang Panda (aka. Stately Taurus//Earth Preta/BRONZE PRESIDENT/TA416/RedDelta),
  NewsPenguin, Prophet Spider, TA2541, TA428, TA551, UAC-0057 (GhostWriter), WIRTE,
  Witchetty Software Association: Agent Tesla, Astaroth, Avaddon, Black Basta, BazarLoader,
  Cring, DarkGate, MirrorBlast, NanoCore, PoetRAT, QakBot, RATDispenser, SquirrelWaffle,
  Trickbot, Remcos RAT, WhisperGate, Zloader Atomics T1105 Test #11 Atomics T1059.005
  Test #1 Atomics T1082 Test #9 Atomics T1547.001 Test #5 -- #TrendingThreat #Russia
  #Ukraine'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` (EventCode=1 OR "EventID>1")
  ("cscript.exe" OR "WScript.exe" OR "cscript" OR "wscript") | regex process="(?i)(w|c)script.{1,}?\.\w{2,4}"
  | table _time, host, user process, process_*, parent_*, signature_id | bin span=1s
  | stats values(*) as * by _time, host '
techniques:
- execution:command and scripting interpreter:visual basic
- execution:command and scripting interpreter:javascript
technique_id:
- T1059.007
- T1059.005
data_category:
- Windows Sysmon
references:
- https://secure.anvilogic.com/use_cases?id=AVL_UC1029

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_sysmon` (EventCode=1 OR "EventID>1") ("cscript.exe" OR "WScript.exe" OR "cscript" OR "wscript")

Stage 2: regex

| regex process="(?i)(w|c)script.{1,}?\.\w{2,4}"

Stage 3: table

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

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
  • 1 corpus 237 (splunk 224, kusto 13)
processregex_match
  • "(?i)(w|c)script.{1,}?.\w{2,4}" 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
1"EventID>1"
1"cscript.exe"
1"WScript.exe"
1"cscript"
1"wscript"