Those who haven't bothered to remove the malicious software, however, lost internet access at 12:01 a.m. Monday after the U.S. Federal Bureau of Investigation ended a four-month program to keep them online so they could remove the bug by clicking links like this one.
The FBI estimates that about 277,000 computers are still infected, including about 64,000 in the United States. Owners of these systems can no longer access the Internet and will have to take their hardware to computer repair specialists -- or they can follow the instructions here.
Tom Grasso, an FBI special agent, told Fox News that many Internet service providers have set up ways to assist owners of compromised computers, or have established ways to keep their customers online. Although whatever technical solutions are established by these providers will still require consumers to check for and remove the malware, which can also slow down Internet use by compromised systems.
Those most likely affected are consumers. Company officials told the Wall Street Journal that for the most part they have checked for and resolved any DNS Changer issues. The FBI had estimated that 10 percent of Fortune 500 companies had some computers infected by the malware.
At its peak, DNS Changer Malware had compromised about 650,000 systems simultaneously worldwide. In all, about 4 million computers worldwide had been compromised before the criminal operation was shut down.
The malware was created by a gang of Estonian cyber-crooks working under the name Rove Digital, a company whose sole purpose was to make money selling ads on websites peddling fake products. As the name suggests, DNS Changer altered the domain name system of computers, redirecting them to servers in Estonia, New York and Chicago that altered the results of Internet searches. The malware led people unknowingly to fraudulent websites. The malware installed after users clicked on rigged links.
On Nov. 8, Estonian police working with the FBI shut down the operation. Since then, U.S. anti-cybercrime authorities have been urging computer users to check for and, if necessary, remove the software from their computers. In March, the FBI hired the nonprofit Internet Systems Consortium to set up clean servers that infected computers could use after the crooked servers were taken offline. The court order that allowed this unusual move expired on July 9 and was not renewed.