Microsoft detects and cleans up between 60,000 and 100,000 machines infected with the Zeus Trojan each month, the software giant said.
“…We’re still seeing both distinct malware families out and about in the wild. Between the two, we’re finding that they’re responsible for a significant amount of the e-commerce-related fraud happening at any given time,” said Matt McCormack of the Microsoft Malware Protection Center in Melbourne, Australia. At one point industry scuttlebutt had Zeus morphing into the SpyEye Trojan.
Microsoft snuck more protections from new Zeus malware variants into the latest version of its Malicious Software Removal Tool (MSRT), McCormack said. “This month (carefully hidden under the Win32/Bamital blanket), employing the old adage ‘fight fire with fire’, we decided to fight sneakiness with sneakiness and quietly slipped a fairly major Win32/Zbot update into MSRT.”
The software giant detected 103,391 Zeus-infected machines in March; 113,814 in April; 60,385 in May; 83,555 in June; 61,323 in July; and 89,994 in August.
Microsoft “felt it was time to turn the screws tighter on Zbot again” given the steady stream of infections this year, he said.
Security researchers have been closely watching for samples of a merged version of Zeus and SpyEye ever since “Slavik” or “Monstr,” the author of Zeus, last year gave the source code to another crimeware author, “Gribodemon,” a.k.a. “Harderma.”
Trend Micro researchers earlier this year got their hands on a sample of the SpyEye builder that included an administration panel including some lines of Zeus code. The two malware families would make a powerful combination. Zeus was able to remove some security applications, SpyEye was not.