The notorious Rock Phish gang has added a new twist to its phishing exploits that doesn’t require its victim to visit a malicious Website -- instead, it just loads a malicious keylogging Trojan onto the victim’s machine that steals information or credentials.

Both Trend Microand F-Secure over the past few days spotted new iterations of the attack, which was first reported by RSA last week. The latest tack is phishing emails posing as Comerica Bank and Colonial Bank that ask banking customers to renew their digital certificates. When they click on the link for more information on the phony renewal process, it downloads the nasty Trojan onto their desktops.

"In a way, it’s so blatant that it reminds me of the worms of ’04 and ’05… such as Bagel. They would come via email, and you’d receive an executable file" in them, says Jamz Yaneza, threat research project manager for Trend Micro.

The danger of the so-called Zeus Trojan is that it can execute what Yaneza calls a "long-term" phishing attack on the victim. "It can stay there and log credentials, personal information, and steal personal information. Basically anything you type," he says. The version Trend has been studying has the ability to receive downloaded updates to itself, he says.

F-Secure says the email lures the user into hitting the “continue” link in the message to update the digital certificate, and then provides a “page full of jargon designed to overwhelm the potential victim. What happens if the victim falls for the bait and installs the ‘certificate?’ A trojan-spy will be installed,” F-Secure wrote in its blog today. “So now the phishers don't need to ask for passwords anymore, they can just take them.”

Like most sophisticated malware designers, the Rock Phish group also has been coming out with different versions of the malware each day to try to fly under the radar. It changes the “packer,” encoding, and other characteristics to evade antivirus detection, according to Trend Micro’s Yaneza. Some versions can monitor FTP transactions, email, and instant messaging conversations.

And in the spirit of an emerging crimeware-as-a-service market, the Rock Phish gang is also selling Zeus as a crimeware service -- with a service guarantee and user licensing agreements, according to Trend Micro. “It comes with its own tech support. There’s a phone number you can call out there in the Ukraine,” Yaneza says. (See New Crimeware-as-a-Service Market Thriving.)

Meanwhile, Paul Ferguson, advanced threat researcher for Trend, says he’s seen a list of 20 new domains using the same phishing attack. “We’re going to see more of this” attack, he says.

Ferguson’s advice to end users is the same-old, same-old: be aware that your bank will never send you anything to download, not even a digital certificate, so don’t fall for one of these emails, he says. “They are not going to ask for your confidential information.”

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