Back in January our company and job site was hit with a nasty nasty virus. In 5 minutes it hit 1200 servers and 17000 computers. It took our entire IT staff (~150 people), forensic experts from Microsoft, and expert staff from Symantec 3 weeks before recovery could even begin. Every time they rebuilt something and got it back on an isolated domain it would get infected again and instantly encrypt and attempt to send the data to cyber land then the hard drive would wipe itself clean (they think it was Syria or Turkey). Definitely a targeted attack as it only hit chemical and oil companies in the region. Some of these viruses are NO BUENO. A similar virus hit our parent company a couple years ago and they just ordered 30,000 hard drives and replaced everything top to bottom.