SpyEye Changes Phone Numbers to Hijack Out of Band SMS Security

Via Trusteer Blog (Oct 5, 2011) -

The Trusteer research team recently uncovered a stealth new attack carried out by the SpyEye Trojan that circumvents mobile SMS (short message service) security measures implemented by many banks. Using code we captured while protecting a Rapport user, we discovered a two-step web-based attack that allows fraudsters to change the mobile phone number in a victim’s online banking account and reroute SMS confirmation codes used to verify online transactions. This attack, when successful, enables the thieves to make transactions on the user’s account and confirm the transactions without the user’s knowledge.

[...]

Out-of-Band is not a Panacea

This latest SpyEye configuration demonstrates that out-of-band authentication (OOBA) systems, including SMS-based solutions, are not fool-proof. Using a combination of MITB (man in the browser injection) technology and social engineering, fraudsters are not only able to bypass OOBA but also buy themselves more time since the transactions have been verified and fly under the radar of fraud detection systems. The only way to defeat this new attack once a computer has been infected with SpyEye is using endpoint security that blocks MITB techniques. Without a layered approach to security, even the most sophisticated OOBA schemes can be made irrelevant under the right circumstances.