Detection rules › Splunk
CMD execution with _c (PowerShell)
The cmd.exe /c command is used to execute a specific command and then terminate the command prompt (CMD) window and is commonly seen in both legitimate and malicious scripted processes. Attackers may use /c after commands to avoid detection
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1059.003 Command and Scripting Interpreter: Windows Command Shell |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| PowerShell | Event ID 4104 | Creating Scriptblock text (MessageNumber of MessageTotal). |
Rule body yaml
id: '21846.38507'
title: CMD execution with _c
description: 'The cmd.exe /c command is used to execute a specific command and then
terminate the command prompt (CMD) window and is commonly seen in both legitimate
and malicious scripted processes. Attackers may use /c after commands to avoid detection.
-- Threat Actor Association: Mustang Panda (aka. Stately Taurus//Earth Preta/BRONZE
PRESIDENT/TA416/RedDelta), Volt Typhoon - Software Association: DarkGate, Snatch
-- Atomics T1036 Test #2 Atomics T1059.003 Test #5'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4104) OR
"<EventID>4104<") "cmd.exe" "/c" | regex process="(?i)cmd(\.exe(\"?))?\s+\/c\s+"
| table _time, host, user, process, process_*, parent_process, parent_process_*,
user | bin span=1s | stats values(*) as * by _time, host '
techniques:
- execution:command and scripting interpreter:windows command shell
technique_id:
- T1059.003
data_category:
- PowerShell logs
references:
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1036/T1036.md#atomic-test-2---malware-masquerading-and-execution-from-zip-file
- https://twitter.com/ffforward/status/1481672378639912960
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4104) OR "<EventID>4104<") "cmd.exe" "/c"
Stage 2: regex
| regex process="(?i)cmd(\.exe(\"?))?\s+\/c\s+"
Stage 3: table
| table _time, host, user, process, process_*, parent_process, parent_process_*, user
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.
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>4104<" |
| 1 | "cmd.exe" |
| 1 | "/c" |