Some computer users have until July 9 after to make sure they're not the victims of what FBI officials called a sophisticated international hacking ring that launched an online advertising scam.
The problem began when the hackers took control of computers around the world and infected them with malware called DNSChanger, according to the FBI. The hackers infected a network of probably more than 570,000 computers worldwide.
Click here to view an FBI flowchart of how the scam worked.
Most victims don’t even know their computers have been infected, although the malicious software probably has slowed their Web browsing and disabled their antivirus software.
The FBI set up a temporary safety net last year using government computers that replace the malicious servers used by the hackers. But the safety net is set to expire on July 9 because it was only intended to allow users time to clean affected computers and restore DNS settings.
Some affected computers might lose connectivity on July 9, according to the FBI.
The FBI is encouraging users to visit a website run by its security partner that will inform them whether they’re infected and explain how to fix the problem.