The internet security experts from ESET company have discovered a new version of the BackSwap banking trojan. So far, the malware has been targeting the clients of five Polish banks: PKO Bank Polski, Bank Zachodni WBK S.A., mBank, ING, and Pekao.

However, due to its effectiveness, the researchers are convinced that the new trojan is bound to spread to other banking systems in the upcoming future.

The new strain is considered to be highly dangerous because it implements a new technique to steal money from bank customers. In short, the BackSwap Trojan can change the account numbers in online transfers system. The entire operation is done without the account holder’s knowledge.

This is a seemingly simple trick that nevertheless defeats and bypasses all of the anti-malware solutions and security features implemented by browsers. The current versions of the BackSwap Trojan could be used against most popular browsers such as Google Chrome, Mozilla Firefox and Internet Explorer.

The experts from ESET company have notified all browser vendors about BackSwap's new technique to help them develop effective countermeasures in upcoming browser versions.