PRB-Backdoor - A Fully Loaded PowerShell Backdoor with Evil Intentions
INTRODUCTION The great people at ClearSky reached out to me a couple of days ago regarding a sample that they suspected could be related to MuddyWater. They suspected so because the sample had some similarities with the way MuddyWater lures look like and some similarities in some PowerShell obfuscation, in specific the character substitution routine. MuddyWater Sample New Sample However, after analyzing the sample and investigating it more, I was able to showcase that this is indeed something different but nonetheless interesting. This blog is a walk through my analysis and will highlight initial insights into this potential attack. THE SAMPLE - FROM AIRMILES TO MACRO CODE TO POWERSHELL The sample that was shared with me is a macro laced word document called "Egyptairplus.doc " with an MD5 hash of fdb4b4520034be269a65cfaee555c52e . The macro code contains a function called Worker() which calls multiple other functions embedded in the document to u