In this short post, we share a YARA rule that threat hunters will find valuable for identifying potentially malicious Powershell pivots. Specifically, we'll be looking for base64 encoded Powershell directives. Additionally, some interesting real-world samples will be shared with the reader. Including an SSL certificate, Microsoft Windows shortcut (LNK) file, and a JPG image.
In this article, we dissect a sophisticated multi-stage PowerShell script that was found on HybridAnalysis a few days back. The discussion entails an in-depth analysis of the various techniques that this particular malware instance utilized to keep itself under the radar. As of writing this article, none of the AntiViruses on VirusTotal detected this sample.