MediumSigmaHQ frack113

Suspicious FromBase64String Usage On Gzip Archive - Ps Script

Detects attempts of decoding a base64 Gzip archive in a PowerShell script. This technique is often used as a method to load malicious content into memory afterward.

Detection logic

Detection requirements

Platform: ESXi Linux macOS Windows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
Log source product: windows
Log source category: ps_script

Known benign triggers

Legitimate administrative script

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
speakerdeck.com/heirhabarov/hunting-for-powershell-abuse?slide=43	Unclassified	2

Detection rules

Suspicious FromBase64String Usage On Gzip Archive - Ps Script

Detection logic

Detection requirements

Known benign triggers

MITRE ATT&CK mappings

References

From the source

Licence

Authorship

Detection rules