New Pushdo variant infects more than 100k computers
A new variant of the revived Pushdo trojan has infected more than 100,000 computers since the beginning of August, and it's using a new technique to trip up researchers trying to study the botnet.
As is the case with most botnet scenarios, computers that are infected with Pushdo attempt to communicate with their command-and-control server for instructions. The twist here is that the botmasters have customized the malware so that it simultaneously delivers HTTP requests to some 300 lesser known, but legitimate, websites, which mixes in with traffic meant for the command-and-control hub, said Brett Stone-Gross, a senior security researcher at Dell SecureWorks Counter Threat Unit.
"The purpose of the HTTP requests to legitimate sites is to make it harder to identify C2 (command-and-control) traffic, [which] also uses HTTP," Stone-Gross told SCMagazine.com on Wednesday. "As a result, security researchers have to sift through all of the HTTP requests in order to locate the C2, which is important for detection and mitigation efforts."
