According to Bloomberg coverage of gray-beard security guru Gunter Ollmann, botnet malware controls 7% of corporate computers and 1/5th of US personal computers: “The enslaved 'bots,' as the infected computers are known, have become so pervasive they now threaten the security of the Internet, said Gunter Ollmann, head of research at Atlanta-based Damballa Inc., which tracks botnet activity. At least 18 percent of home computers are now under remote command of cyber-thieves without their owners’ knowledge, according to Damballa’s research. (Read whitepaper here.)
For corporate computers, which are usually protected by expensive security measures, around seven percent are controlled by such malware, which is hidden from the user and controlled via the Internet, Ollmann said.
The FBI dismantled the so-called Coreflood botnet in April. Operated by a gang of Russian cyber-thieves who siphoned financial information off their hosts, agents estimated that the software that controlled it had infected more than 1.8 million computers in the U.S. alone.
The stolen information was used to make bank transfers in some cases of hundreds of thousands of dollars, the Justice Department said. Thieves attempted to transfer more than $934,000 from an unnamed defense contracting company in Tennessee in one case. They removed $78,421 from the bank account of an unidentified law firm in South Carolina and $115,771 from an unidentified real estate company in Michigan, according to court papers.”