Additional help comes from a loose coalition of security vendors and others called the Conficker Working Group, which has banded together to block access to domains that Conficker is trying to communicate with. But it's not immediately clear whether those efforts, which have been successful at blocking earlier versions of the worm, will be effective against the activation of Conficker.c.

"We can't really say how successful the attempts at blocking them or not routing them are," Dirro said. "That's something we'll see when the first domain actually starts serving malware, if at least one starts doing that."

Despite the uneventful passing of the activation deadline, the threat presented by Conficker remains real.

"These guys are very sophisticated, very professional, very determined and very measured in how they implement and make changes to things," Ferguson said, adding that Conficker.c is better defended and more survivable than previous versions of the worm. "This activation on April 1 was probably just arbitrary and picked to cause hysteria."

At some point, the people behind Conficker.c could try to generate revenue from the botnet they've created or they could have other intentions.