Detection rules › Splunk
Command Line Spawned by Archive Utility - Windows (Sysmon)
This use case detects command line utility executions with an archive utility as a parent process. CVE-2023-38831
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1059 Command and Scripting Interpreter, T1204.002 User Execution: Malicious File |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
Rule body yaml
id: '21030.37461'
title: Command Line Spawned by Archive Utility - Windows
description: 'This use case detects command line utility executions with an archive
utility as a parent process. CVE-2023-38831 -- Threat Actor Association: APT28,
APT40, Sandworm Team, UAC-0057 (GhostWriter)'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "<EventID>1<")
("winrar.exe" OR "rar.exe" OR "7z*.exe" OR "peazip.exe" OR "powerarc.exe" OR "bandizip.exe"
OR "zipware.exe" OR "winzip.exe" OR "powershell.exe" OR "cmd.exe" OR "wscript.exe"
OR "cscript.exe" OR "regsvr32.exe" OR "rundll32.exe" OR "wmic.exe" OR "control.exe")
| where match(parent_process_path, "(?i)(winrar|rar|7z.*|peazip|powerarc|bandizip|zipware|winzip*)\.exe")
and match(process_name, "(?i)(powershell(_ise?)|pwsh|cmd|wscript|cscript|regsvr32|rundll32|wmic|control)\.exe")
| table _time, host, user parent_*, process, process_* | bin span=1s | stats values(*)
as * by _time, host '
techniques:
- execution:command and scripting interpreter
- execution:user execution:malicious file
technique_id:
- T1059
- T1204.002
data_category:
- Windows Sysmon
references:
- https://www.group-ib.com/blog/cve-2023-38831-winrar-zero-day/
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "<EventID>1<") ("winrar.exe" OR "rar.exe" OR "7z*.exe" OR "peazip.exe" OR "powerarc.exe" OR "bandizip.exe" OR "zipware.exe" OR "winzip.exe" OR "powershell.exe" OR "cmd.exe" OR "wscript.exe" OR "cscript.exe" OR "regsvr32.exe" OR "rundll32.exe" OR "wmic.exe" OR "control.exe")
Stage 2: where
| where match(parent_process_path, "(?i)(winrar|rar|7z.*|peazip|powerarc|bandizip|zipware|winzip*)\.exe") and match(process_name, "(?i)(powershell(_ise?)|pwsh|cmd|wscript|cscript|regsvr32|rundll32|wmic|control)\.exe")
Stage 3: table
| table _time, host, user parent_*, process, 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.
| Field | Kind | Values |
|---|---|---|
EventCode | eq |
|
parent_process_path | match |
|
process_name | 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 | TERM |
| 1 | "<EventID>1<" |
| 1 | "winrar.exe" |
| 1 | "rar.exe" |
| 1 | "7z*.exe" |
| 1 | "peazip.exe" |
| 1 | "powerarc.exe" |
| 1 | "bandizip.exe" |
| 1 | "zipware.exe" |
| 1 | "winzip.exe" |
| 1 | "powershell.exe" |
| 1 | "cmd.exe" |
| 1 | "wscript.exe" |
| 1 | "cscript.exe" |
| 1 | "regsvr32.exe" |
| 1 | "rundll32.exe" |
| 1 | "wmic.exe" |
| 1 | "control.exe" |