I had to clean a bunch of flash drives for a project this morning and I noticed one folder was not being cleaned. It was called Pozuda and of course it had a desktop.ini inside there that made the folder look like the Recycle Bin. Therefore, when you click on it, the folder takes you to the Recycle Bin as well.
I scanned the folder on my laptop (MacBook, Windows 7) with Avast Home (4.8.1355, defs from today), and it didn't find anything. I knew there was something in there, because it was 150 kb, which is too much for just a .ini file.
I scanned the same flash drive on another computer with up to date AVG 9.0 (just reformatted last night). Nothing.
I scanned the same flash drive on another computer with up to date Bit Defender Business Client (enterprise ed). Nothing.
So I rebooted into Mac, and of course, there inside the folder was a file called malena.exe. I've removed both the autorun.ini and the Pozuda folder and have them sitting here on my Mac.
Why the hell couldn't these three (reputable) AVs detect it?
Edit: I'm seeing a lot of these things that Avast isn't removing, so I'm semi-seriously thinking about just running Mac OS all the time on my laptop (and using VMs for my dev work). It'll be hard, as I've been using Windows about 99% of the time now. And maybe Ubuntu for the desktop back at home. What a bugger. WTF Windows/AV vendors?