It's not only Zeus that online bank account users should be wary of. We users need to pay attention to obscure data-theft Trojans such as 'Bugat', 'SpyEye', and 'Carberp', according to security firm Trusteer.
In recent weeks, the Zeus banking Trojan has attracted all the attention with news of a number of successful online bank account raids, but other threats lurk, the security company says.
One example is Bugat, on the face of it not the most frightening bank Trojan in circulation. Its incidence is low, and its incursions seem for the time being to be focussed on banks in the US rather than Europe.
However, according to Trusteer, there are signs that Bugat could now be favoured over the better-known Zeus, starting with a campaign from last week in which LinkedIn users were spammed as a method of spreading a new version further afield.
A similar attack was pioneered only days before that by Zeus, so such targeted Trojans could start to merge into one generalised threat distributing hard-to-block malware using identical channels.
"We are in an arms race with criminals. Although Zeus gets a lot of attention from law enforcement, banks and the security industry, we need to be vigilant against new forms of financial malware like Bugat and SpyEye which are just as deadly and quietly expanding their footprint across the internet," said Trusteer CEO, Mickey Boodaei.
The threat is that new versions of these Trojans keep appearing, which makes detection trickier. The inherently stealthy nature of such malware means that they can appear to be relatively inactive while doing great damage, as was the case with Zeus.
Trusteer's view is that bank Trojans need to be countered in the browser with tools such as its own Rapport plug-in rather than using conventional antivirus software. Other companies seem keen to jump on this approach with their own plug-ins and tools.