A malicious bit of software called DNSChanger has infected hundreds of thousands of computers over the last five years, linking the computers together into a massive botnet, which malicious hackers used to re-directed Web users to fraudulent websites that stole financial information like credit card numbers – all without the computer owner’s knowledge. The San Jose Mercury News reports that the epidemic has been contained to 70,000 computers, down from 500,000 at the peak since the malware first appeared in 2007. The FBI busted the hacker ring that was responsible, but the agency loses legal authority to keep the hackers’ servers running on Monday. If your machine is infected, it will get kicked off the Web. Sophos security released this video Friday explaining how to avoid this fate.