Thousands could lose Internet access on Monday, July 9 because of a virus, DNSChanger, which at one time infected approximately 4 million computers worldwide.

The Federal Bureau of Investigation first announced the details about the virus in November when they arrested the malware’s authors.  The virus affects computers’ abilities to correctly access the Internet’s DNS system, which is like a phone book.

The virus would redirect Internet users to fake DNS servers, sending them to fake sites. Once the FBI shut it down, it built a safety net of new servers to redirect traffic from those infected with the virus.

The safety net is going offline this Monday meaning anyone with a computer that is still affected will lose Internet access unless they remove the virus.

To see if you have the virus, go to a checker Web site such as DNS Changer Working Group or the FBI’s site to enter your IP address or run a check against addresses known to have problems.