Now tagged by at least one security firm as "the worst worm in history," Mydoom has created a back door to infected systems that an army of hackers is quickly turning to its advantage.
Mydoom, which began spreading on Monday, continues to show signs of slowing, according to some security analysts, while others disputed that take.
"We're still seeing a substantial number of Mydoom submissions [from customers]," said Eric Chien, chief researcher with Symantec's Security Response team. "The volume really hasn't gone down that much; it will take a few more days for it to taper off."
Network Associates' AVERT team, meanwhile, said Wednesday that Mydoom isn't slowing down, and increased its estimates of infected systems from the 100,000 to 200,000 of yesterday to a whopping 400,000 to 500,000 today.
Even before today, Mydoom had broken records once held by Sobig to become the fastest-spreading worm ever, several security and messaging filtering firms have said. The latest to award Mydoom the dubious distinction is the Finnish company, F-Secure, which now estimates that 20 to 30 percent of all global e-mail traffic is composed of Mydoom mailings.