Not sure who needs to know this, but if you download and install the Windows version of Rufus, the free software for writing ISO images to USB/CD-ROM, your PC will end up with about 100 trojans.
Edit: The site I downloaded from was rufus[.]ie which is apparently the official site. During installation, the software threw up a couple of rather verbose messages saying it needed to download additional components.
@briankrebs
Think I pulled down Rufus a couple of months back for a one off. Don't recall where I got it from, but didn't notice any untoward behavior, so possibly a more recent compromise?