This graphic shows how the DNSChanger malware worked.
The U.S. Department of Justice said today that it has uncovered a large, sophisticated Internet scam ring that netted $14 million by infecting millions of computers with malware designed to redirect their Web searches to sites that generated ad revenue.
Six people have been arrested in Estonia and a Russian is being sought on charges of wire fraud and computer intrusion, the FBI said. They are accused of infecting about 4 million computers in more than 100 countries–500,000 in the U.S. alone, including NASA–with malware called DNSChanger. The malware altered the Domain Name Server settings on the computers so they could be automatically redirected to rogue DNS servers and then on to specific Web sites.
In essence, the malware hijacked the computers when certain Web searches were done, redirecting them to sites that would pay them money when people visited or clicked on ads.
“When users of infected computers clicked on the link for the official Web site of iTunes, for example, they were instead taken to a Web site for a business unaffiliated with Apple Inc. that purported to sell Apple software,” an FBI statement said.
In addition, the malware would redirect infected computers searching for Netflix to a business called “BudgetMatch” and searches or the IRS to H&R Block, according to the FBI.
Defendants also allegedly replaced legitimate ads on sites with ads that triggered payments to them. For instance, they are accused of replacing an American Express ad on the Wall Street Journal home page with an ad for “Fashion Girl LA,” and an Internet Explorer 8 ad on Amazon.com with one for an e-mail marketing firm.
Computers became infected with DNSChanger when they visited certain Web sites or downloaded particular software to view videos online. In addition to altering the DNS server settings, the malware also prevented antivirus and operating systems from updating, according to officials.
The defendants allegedly created companies that masqueraded as legitimate advertising publisher networks. The operation began in 2007 and ended in October with the completion of the two-year FBI investigation called “Operation Ghost Click,” the FBI alleges.
The rogue DNS servers used in the operation have been replaced with legitimate servers in the hopes that infected computers will still be able to access the Internet. Owners of infected computers will need to clean the malware off their machines. People can see if their computer is infected by typing in their DNS information on this FBI Web page.
The indictment filed in the U.S. District Court of New York was unsealed today.