By Andrew Brandt
It’s been a long time since I’ve worked on a malware file as singularly obnoxious as Worm-Shiv, a new worm we defined a few weeks ago. There isn’t anything especially technically avant-garde or advanced about the worm, nor was it especially difficult to detect or remove. It just exhibits behavior that, to be blunt, is about as annoying as it possibly can be.
The infection process starts with a small self-extracting RAR archive executable. When run, it drops and executes another .exe file, which in turn drops and executes yet another .exe file. Sounds pretty unobtrusive so far, right?
Well, even though the worm might have snuck by unnoticed, it would be hard to characterize its operational behavior as “staying below the radar.” The worm puts a copy of a file named wsock32.dll into every single folder on the hard drive. Every. Single. One. On my test system there were more than 200 copies left behind.
Then the fun begins.