Warnings have been made of a new wave of malicious email messages that carry a Zeus payload.
Websense said that when viewing the deobfuscated content, it saw that the script uses a meta refresh tag to redirect a user who views the attachment. The script checks which browser is used and only performs the redirection if Firefox, Chrome or Safari is used. A user who is using one of the affected browsers will get redirected to a pharmaceutical site.
The 'label.zip' file contains 'label.exe', which is a copy of Zeus. The malware copies itself to C:\Documents and Settings\user\Application Data\Ewca\refef.exe and tries to access two sites located in the .ru zone.
Carl Leonard, senior manager of Websense Security Labs, said: “This is a great example of a blended threat that covers all attack angles – web, email and file-based, and steals your data to boot. In this campaign, a mail recipient may get a message to say $375 has been sent to their account, and include a link to view the transaction. So far, we have seen more than 100,000 email messages like this, and counting.”
The announcement came as BitDefender released its Zbot/Zeus removal tool. The Zbot Removal Tool can be downloaded from the 'Removal Tools' section of malwarecity.com, a BitDefender initiative for the software security community and a free resource for those interested in their online security.
Catalin Cosoi, head of the BitDefender online threats lab, said: “The removal tool checks users' computers, detects and eliminates most of the Zbot variants spotted in the wild and it is available for download free of charge.
“As Zbot is one of the most prolific breeds of malware and new variants appear everyday, we strongly suggest that computer users regularly return to our removal tool page on malwarecity.com for additional updates of the Zbot Removal Tool."