Tuesday, November 10, 2009
FireEye Moves Quickly to Quash Mega-D Botnet
FireEye, a California company that makes security appliances, had been tracking a botnet called Mega-D or Ozdok. Mega-D, which is a network of hacked computers, has been responsible for sending more than 4 percent of the world's spam, according to M86 Security. Many of the computers that make up Mega-D are infected home PCs.
Mega-D is one of several botnets that have implemented advanced technical measures to ensure its owners don't lose control of the hacked PCs. The hackers use command-and-control servers to issue instructions to the zombie PCs, such as when to run a spam campaign.
In the case of Mega-D, the hacked PCs will look for certain domain names in order to download instructions, wrote Atiq Mushtaq of FireEye on the company's blog. If those domains aren't active -- they are often shut down by ISPs if they're associated with abuse -- Mega-D machines will look for custom DNS (Domain Name System) servers to find live domains.
If that also fails, Mega-D is programmed to generate a random domain name based on the current date and time, Mushtaq wrote. When the hackers register the domain name, the infected machines can visit there to get new instructions. PC World