I found a copy of the virus that was used to exfiltrate data from Sony Entertainment's computers and then wipe them (supposedly the virus was developed by North Koreans, in response to the movie The Interview, but actually, my own forensics suggest that the authors were South Korean). In the process of studying the virus, I must have accidentally double-clicked on the executable in Nautilus when I was trying to drag it to move it into another directory. For whatever stupid reason, Nautilus is set up to run Windows executables in Wine when they are double-clicked. A couple of minutes later, I noticed files were starting to disappear all over my hard drive. I panicked and held down the power button for 5 seconds to hard-shutdown the computer. Sure enough, when I rebooted, I discovered that tens of thousands of files were gone. It's a real victory for Linux compatibility with Windows when Wine can run viruses just as well as Windows.