DNSChanger is a nasty piece of malware that – according to the FBI – still infects more than four million computers worldwide.

When the FBI arrested the people responsible for creating and controlling DNSChanger, they realized that taking down the servers controlling the malware would interrupt Internet access for computers still infected. So they left the DNSChanger servers up, but disabled the malware’s ability to spread further. They issued warnings to the general public, stating that they intended to shut down the DNSChanger servers on July 9, 2012. That day is approaching.

To avoid having your computer essentially cut off from the Internet on Monday, you should use one of the many available DNSChanger detection sites to determine whether your computer is infected. In the unlikely event that your computer is found to be infected, instructions and tools for removal of DNSChanger are available.