Detection rules › Splunk
PowerShell Hidden Window (Windows Event Log)
Threat actors may attempt to conceal their activity involving PowerShell windows by setting the WindowStyle parameter to hidden. While legitimate administrative tasks may use hidden windows to perform maintainence tasks in the background, this technique can be used by threat actors to evade user suspicion and reduce the likelihood of detection. This use case detects PowerShell executions involving hidden window commands. PowerShell logging is recommended for detection; process creation logs will only detect this activity if the command is executed in a manner that creates a new process, such as powershell -c. Atomic Test T1564.003 - Test #1
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1059 Command and Scripting Interpreter |
| Stealth | T1564.003 Hide Artifacts: Hidden Window |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
id: '39125.70662'
title: PowerShell Hidden Window
description: 'Threat actors may attempt to conceal their activity involving PowerShell
windows by setting the WindowStyle parameter to hidden. While legitimate administrative
tasks may use hidden windows to perform maintainence tasks in the background, this
technique can be used by threat actors to evade user suspicion and reduce the likelihood
of detection. This use case detects PowerShell executions involving hidden window
commands. PowerShell logging is recommended for detection; process creation logs
will only detect this activity if the command is executed in a manner that creates
a new process, such as powershell -c. Atomic Test T1564.003 - Test #1'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
"<EventID>4688<" OR Type=Process) ("-WindowStyle" OR "-w") "hidden" | regex process="(?i)-w(indowStyle)?\s+hidden"
| table _time, host, user, process, parent_process_name | bin span=1s | stats values(*)
as * by _time, host '
techniques:
- defense-evasion:hide artifacts:hidden window
- execution:command and scripting interpreter
- defense-evasion:hide artifacts
technique_id:
- T1564.003
- T1059
- T1564
data_category:
- Process command-line parameters
- Windows event logs
references:
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1564.003/T1564.003.md#atomic-test-1---hidden-window
- https://thedfirreport.com/2023/10/30/netsupport-intrusion-results-in-domain-compromise/
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR "<EventID>4688<" OR Type=Process) ("-WindowStyle" OR "-w") "hidden"
Stage 2: regex
| regex process="(?i)-w(indowStyle)?\s+hidden"
Stage 3: table
| table _time, host, user, process, parent_process_name
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>4688<" |
| 1 | "-WindowStyle" |
| 1 | "-w" |
| 1 | "hidden" |