The Banker-AJ Trojan targets users of UK online banks such as Abbey, Barclays, Egg, HSBC, Lloyds TSB, Nationwide and NatWest. The malware records passwords and keystrokes once users of infected machines visit targeted websites. This data is then surreptitiously transmitted to crooks, allowing fraudsters to later empty bank accounts.
People are increasingly aware of the threat from phishing emails which direct innocent users to fake banking websites in order to capture personal details, but this Trojan is different - it waits until the user visits a real banking website and then surreptitiously monitors the login process," said Graham Cluley, senior technology consultant at Sophos. "It's like having a mugger looking over your shoulder as you type in your PIN number."
Sophos said that the techniques used by the Banker-AJ Trojan are a repeat of tactics previously used by malware authors to gain access to Brazilian online bank accounts.
The use of malicious code and phishing scams to extract confidential account details from consumers have cost British banks more than 4.5m over the last year, according to estimates from banking group APACS published last months. APACS and UK police warn that the use of malicious code in such attacks in beginning to eclipse conventional phishing attacks in its severity.