The move this month by regional Internet registry RIPE to reallocate the tainted IP addresses caught the DNS Changer Working Group (DCWG) and others in the industry by surprise. The DCWG -- an ad hoc group made up of members from Georgia Tech, Internet Systems Consortium, Mandiant, National Cyber-Forensics and Training Alliance, Neustar, Spamhaus, Team Cymru, Trend Micro, the University of Alabama at Birmingham, and other organizations -- helped run the temporary DNS servers that replaced the malicious Rove Digital ones used in the DNSChanger operation.
The FBI, via the Internet Systems Consortium (ISC), controlled those formerly malicious IP addresses from November 2011, after the takedown and arrest of the operators, until July 9, when the FBI shut down the temporary DNS servers that were meant as a stopgap until as many victims as possible had been alerted and remediated.
The FBI's "Operation Ghost Click" last year dismantled the scheme and indicted six Estonians and one Russian allegedly involved in infecting users and redirecting their computers to phony websites in a click-fraud scam. There were initially millions of infected machines, and the malware has been around for several years -- initially targeting home routers.
Paul Vixie, chairman and founder of the Internet Security Consortium (ISC), says RIPE should have held onto the IP addresses a minimum of 12 months before they reallocated them. They won't be much use to the recipients, anyway, because they remain "widely blackholed," he says.
There's another risk, as well, according to Barry Greene, a volunteer with the DNS Changer Working Group: "Of course, there are still 200,000 to 300,000 computers still infected, and they could all be reacquired if someone says, 'Hey, give me those blocks of IP addresses'" and abuses them for nefarious purposes of their own, he says.
"But we are monitoring that to see if any criminals do that," Greene says.
Greene says he's still unclear on just why RIPE decided to reallocate the IP addresses: The organization has a court proceeding scheduled for late November after requesting clarification of Dutch authorities' orders to lock down registration of those IP addresses.
RIPE issued a statement on its decision last week: "After receiving independent legal advice that the police order had no sufficient legal grounds to force the RIPE NCC to execute the order, the RIPE NCC unlocked the blocks of IPv4 address space on 10 January 2012," the statement said, in part. "Two of the four address blocks included in the police order (188.8.131.52/21 and 85.255.112/20) were reallocated after the contractual relationship with the member holding the address space was terminated. The member's account was closed and the space was deregistered ... The address space was quarantined for six weeks before being returned to the RIPE NCC's available pool of IPv4 address space. It was then randomly reallocated to a new resource holder according to normal allocation procedures."
Have a comment on this story? Please click "Add Your Comment" below. If you'd like to contact Dark Reading's editors directly, send us a message.