The resurfaced GameOver bot is back with a vengeance, having infected 12,000 computers after the network was taken down in June, according to Arbor Networks.
The bot was taken out in June in a coordinated and high-profile crackdown by security companies and the FBI and Europol. Servers and domains were seized, disrupting both GameOver Zeus and the CryptoLocker distribution network – although it later staggered back from the dead.
Researchers Dave Loftus and Dennis Schwarz found the bot, now reborn as newGOZ, had ramped up its defences, dumping command and control for a more robust domain generation algorithm (DGA) and a fast flux DNS technique.
The DGA registered new domains based on time and date to make the bot more elusive.
However, researchers from across the security industry have been able to crack the DGA configurations and register the domains before newGOZ had a chance to do so, meaning the researchers would receive – and thus be able to study – traffic from compromised machines.
Abor set up a network of these sinkholes to gain five days' worth of bot intelligence.
"Four days after the discovery of newGOZ, our first sinkhole saw 127 victims," the pair wrote.
"On July 25, we saw a 1,879 per cent increase to 8,494 victims. In aggregate and over three weeks, our five sinkholes saw 12,353 unique source IPs from all corners of the globe."
The boom was due to the use of the Cutwail bot to distribute newGOZ with 42 per cent of infections residing in the United States followed by India with 22 percent.
It targeted mostly internet service providers and others operating in the telco space.
The continued life of the bot demonstrated what many in the security space already knew - that botnet takedowns could only deliver a coup de grâce if bot masters were arrested. ®