Original URL: http://www.theregister.co.uk/2014/06/17/another_rat_crawls_out_of_the_malware_drain/

Another RAT crawls out of the malware drain

Dyreza/Dyre MITMs SSL sessions

By Richard Chirgwin

Posted in Security, 17th June 2014 05:33 GMT

Yet another banking trojan has appeared, using browser hooking to steal data from Internet Explorer, Chrome and Firefox users.

Dyreza, or Dyre, is pitched the usual way, via a phishing e-mail (a lesson that's never learned well enough for the approach to fail), and the e-mail contains what purports to be a zipped document that actually drops the malware payload.

Danish researchers CSIS say they've identified command and control servers, and were able to view money-mule accounts in Latvia associated with on of the servers. CSIS also warns that the payload's code suggests a future attack is planned, in which th phishing e-mail will purport to be a Flash Player update.

The extra sauce in Dyreza is that it tries to launch a man-in-the-middle attack to capture traffic users think is encrypted, and tries to crack two-factor authentication.

An infected user's browser traffic is controlled by the attackers, writes CSIS's Peter Kruse, meaning attackers “are able to read anything, even SSL traffic in clear text. This way they will also try to circumvent 2FA.”

PhishMe, which calls the Trojan Dyre, says the infected user will believe they're establishing SSL sessions, but the “attacker can bypass the SSL mechanism of a web page”.

That's because the malware intercepts user requests and redirects them to IPs the attackers control.

Both PhishMe and CSIS believe it's a new RAT (remote access trojan) rather than another Zeus variant. CSIS has identified Bank of America, Natwest, Citibank, RBS and Ulsterbank as target institutions, but there may be more. ®