MediumSplunk security content Michael Haag +1

Powershell Fileless Process Injection via GetProcAddress

Description

The following analytic detects the use of `GetProcAddress` in PowerShell script blocks, leveraging PowerShell Script Block Logging (EventCode=4104). This method captures the full command sent to PowerShell, which is then logged in Windows event logs. The presence of `GetProcAddress` is unusual for typical PowerShell scripts and often indicates malicious activity, as many attack toolkits use it to achieve code execution. If confirmed malicious, this activity could allow an attacker to execute arbitrary code, potentially leading to system compromise. Analysts should review parallel processes and the entire logged script block for further investigation.

Detection logic

Detection requirements

Platform: Linux macOS Windows
The rule states no platform. This is derived from the 2 ATT&CK techniques it maps to.
Log source category: powershell_script_block_logging_4104

Known benign triggers

Limited false positives. Filter as needed.

References

Links the source published beside this detection. Reference is the link the source wrote, unmodified. Class is decided by this catalogue from the host and path, not stated by the source. Cited by counts published detections citing the same resource, including this one, and the sources beneath it count the repositories this catalogue ingests, which is not the same as independent research.
Reference	Class	Cited by
blog.palantir.com/tampering-with-windows-event-tracing-background-offense-and-defense-4be7ac62ac63	Unclassified	19from 2 sources
help.splunk.com/en/security-offerings/splunk-user-behavior-analytics/get-data-in/5.4.1/add-other-data-to-splunk-uba/configure-powershell-logging-to-see-powershell-anomalies-in-splunk-uba.	Product documentation	15
static1.squarespace.com/static/552092d5e4b0661088167e5c/t/59c1814829f18782e24f1fe2/1505853768977/Windows+PowerShell+Logging+Cheat+Sheet+ver+Sept+2017+v2.1.pdf	Unclassified	17
www.crowdstrike.com/blog/investigating-powershell-command-and-script-logging/	Security research	17
www.splunk.com/en_us/blog/security/hunting-for-malicious-powershell-using-script-block-logging.html	Security research	14

Detection rules

Powershell Fileless Process Injection via GetProcAddress

Description

Detection logic

Detection requirements

Known benign triggers

MITRE ATT&CK mappings

References

From the source

Licence

Authorship

Detection rules