In a blog posted Monday, botnet experts Sean Bodmer and Marshall Vandergrift said that Murofet -- built largely through a variant of the Zeus Trojan -- has been around a few months longer than originally thought, and could be more dangerous than previous Zeus-based botnets.
"It's deadly, compared to previous versions," Bodmer says.
Data collected by Damballa's network of passive DNS monitoring sensors indicates that what Damballa believed to be a new ZeuS variant at the time of analysis was actually Murofet -- and was observed in the wild as far back as August 2010, according to the blog.
"After spending some time digging into historical data sets, we are able to positively identify Murofet's in-the-wild activity back to as early as August 11th, based on its domain generation algorithm output," the bloggers say.
Damballa has been tracking Murofet since its appearance, "but not until we completed a more detailed analysis of the domains we observed were we able to put the pieces together," the researchers say.
In addition, Damballa can attribute some victim IPs of Murofet with ZeuS bot infections prior to the date of Aug. 11, "which could indicate that the bots were redirected from one botnet to another," the blog says.
"Redirection of one botnet to another is typical criminal behavior intended to extend the life and usefulness of the victim asset and to evade detection," the Damballa researchers say.
"It's important to note that we can see that the infected IPs associated [earlier] infections were initially infected by the Jabber Zeus group -- and a few days later, the same victims started spewing Murofet," Bodmer comments. "Even though we cannot definitively say it was that group [known for making most of the new ZeuS modules], we can attribute some of the activity of the victims to that group, which indicates a level of collusion."
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