The FBI has been on the case since 2011after agents busted a ring of computer hackers located in Estonia.
The scam infected hundreds of thousands of computers around the world and controlled them through rogue servers.
The FBI thinks that about 50 major U.S. corporations are also infected.
The hackers would redirect people to different web sites and rack up millions of dollars in illegal fees.
The challenge for the FBI was that if they were to shut down the hackers' servers, they would wipe out the internet connection for all the victims. Instead they set up alternate servers, which took control of the infected computers.
That temporary system is being shut down on Monday. Which means that about 64-thousand computers in the U.S. will be cut off.
The FBI is directing users to a special web site to see if they are infected - www.dcwg.org
The site will check for the virus and tell you how to fix it.