Original URL: http://www.theregister.co.uk/2012/03/01/neloweg_banking_trojan/

Tick-like banking Trojan drills into Firefox, sucks out info

Neloweg spreading across UK, Netherlands

By John Leyden

Posted in Security, 1st March 2012 11:44 GMT

A new banking Trojan is spreading in the UK and the Netherlands, Symantec warns.

Neloweg operates much like its more famous cybercrime toolkit predecessor ZeuS, but with a couple of subtle twists.

"Like Zeus, Neloweg can detect which site it is on and add custom JavaScript. But while Zeus uses an included configuration file, Neloweg stores this on a malicious webserver," Symantec analyst Fred Gutierrez explains.

The malware is designed to snatch online login credentials, primarily (but not exclusively) those for online banking sites. It infects machines by tricking Microsoft Windows users into installing it via a drive-by-download, spam or targeted email, or with the help of other malware.

Neloweg also targets browsers that utilise the Trident (Internet Explorer), Gecko (Firefox) and WebKit (Chrome/Safari) browser engines. In the case of Firefox, the Trojan buries itself, becoming an integral component of the browser on infected machines – rather than a simple extension – a development that makes the Neloweg more stealthy than previous strains of banking malware.

"In the past we have seen threats create malicious extensions," Gutierrez writes. "All users had to do was disable that particular add-on and they would be safe.

"For Neloweg, this is not the case. Since it is a component, it does not appear as an add-on in Firefox’s add-ons Manager, like other extensions and plugins do. Furthermore, because of the way Firefox is designed, Neloweg will be recreated and reinstalled every time Firefox attempts to connect to the Internet." ®