"In some cases, you might be able to filter the traffic ... but in this case you have machines from all over the world," Steve Trilling, senior director of research for security company Symantec Corp., said.
The next target listed in the code of Mydoom.B, a variant of the original virus, is Microsoft Corp.. However, that attack, scheduled to start at 2:19 a.m. EST Feb. 3, is not expected to have much success because very few machines were infected with the second virus.
The original Mydoom is estimated by some experts to have infected a half million machines, while the variant infected substantially less. Both worms, which are a type of virus, were released last week.
"We're talking about hundreds of thousands of infected machines (with the original Mydoom), as opposed to only hundreds of systems infected with the B variant," Schmugar said. "I wouldn't expect Microsoft to suffer even a slowdown."
Even more troubling for many experts than the latest attacks is Mydoom's ability to plant "backdoors" in infected machines. Such programs enable hackers to commandeer the machines to distribute spam, launch more attacks or steal passwords and financial information from computer hard drives.
