Malware Redirects Bank Phone Calls to Attackers
Trusteer have discovered a concerning development in some new Ice IX configurations that are targeting online banking customers in the UK and US / Ice IX is a modified variant of the ZeuS financial malware platform
In one attack captured by Trusteer researchers, at login the malware steals the victim's user id and password, memorable information/secret question answer, date of birth and account balance.
Next, the victim is asked to update their phone numbers of record (home, mobile and work) and select the name of their service provider from a drop-down list. In this particular attack, the three most popular phone service providers in the UK are presented: British Telecommunications, TalkTalk and Sky.
To enable the attacker to modify the victim's phone service settings, the victim is then asked by the malware to submit their telephone account number. This is very private data typically only known to the phone subscriber and the phone company. It is used by the phone company to verify the identity of the subscriber and authorize sensitive account modifications such as call forwarding. The fraudsters justify this request by stating this information is required as a part of verification process caused by "a malfunction of the bank's anti-fraud system with its landline phone service provider".
Amit Klein, CTO of Trusteer said, "As Trusteer discussed in a recent blog, fraudsters are increasingly turning to these post-transaction attack methods to hide fraudulent activity from the victim and block email and phone communication from the bank. This allows attackers to circumvent security mechanisms that look for anomalies once transactions have already been executed by the user."
Deterministic detection security mechanisms like Trusteer Rapport, which search for specific malware Crime Logic footprints before transactions are submitted and allow the online banking application to stop fraud by changing business flows (block money transfers, decline add payee, limit amounts, etc.), are not vulnerable to post transaction attacks.