With the phone number and platform information, the attacker sends a text message to the victim’s phone with a link to a site that downloads what it says is “encryption software” for the device. But it is, in fact, “Zeus in the mobile” (ZITMO) malware—a Trojan crafted for the Android and BlackBerry mobile operating systems that injects itself between the user and the mobile browser and SMS messaging software. With both devices now compromised, the malware waits for the victim to access a bank account, and then immediately transfers a percentage of the victim’s balance to an account set up by the criminals running the botnet.

The malware then intercepts the confirmation text message sent by the bank, forwarding it to the trojan’s command and control server via a relay phone number. The server uses the message to confirm the transaction and withdraw the money. The same process happens every time the victim logs into their bank account, gradually withdrawing money without alerting the user.

Both Checkpoint and Versafe have added signature and behavior detection to their malware protection products that can block Eurograbber. Updating software that is a frequent target for Web “driveby download” exploits—such as Adobe Flash, Java, and Web browsers—can help prevent infection by the malware, as can a healthy amount of paranoia about clicking links in e-mails.