The Backdoor attack The backdoor attack involves establishing a trust relationship through the "pairing" mechanism, but ensuring that it no longer appears in the target's register of paired devices. In this way, unless the owner is actually observing their device at the precise moment a connection is established, they are unlikely to notice anything untoward, and the attacker may be free to continue to use any resource that a trusted relationship with that device grants access to (but note that so far we have only tested file transfers). This means that not only can data be retrieved from the phone, but other services, such as modems or Internet, WAP and GPRS gateways may be accessed without the owner's knowledge or consent. Indications are that once the backdoor is installed, the above SNARF attack will function on devices that previously denied access, and without the restrictions of a plain SNARF attack, so we strongly suspect that the other services will prove to be available also. Nokia 3610 and 7650 are vulnerable to this attack. The memory on those phones can be accessed by a previously trusted ("paired") device that has since been removed from the trusted list. By exploiting this vulnerability an attacker is able to copy all the information on a targeted device, including media files such as pictures and text messages.