The bad news is it can take a day or two actually to fix the problem, Greene told ABCNews.com. That's because the malware is in a deep section of the hard drive called the "boot sector."

"The malware problem out there is nasty, and it's impacted society on multiple levels," Greene said. "It's extremely hard to get rid of. In most companies, if they get infected with it, they throw away the hard drive."

If you can't do that, follow the instructions. They include backing up your files and reinstalling your operating system.

What Do I Do if I Lose Internet on Monday?

The FBI and DCWG recommend contacting your Internet service provider. They'll be able to give you instructions on what to do next.