New MSN Messenger Trojan Spreading Quickly

By Lisa Vaas  |  Posted 2007-11-20 Print this article Print

Updated: An MSN Messenger Trojan is growing a botnet by hundreds of infected PCs per hour.

A Trojan is introducing malware into thousands of computer systems worldwide, and the number is growing by the hour.

The malware is being introduced by MSN Messenger files posing as pictures, mostly seeming to come from known acquaintances.
The files are a new type of Trojan that has snared several thousand PCs for a bot network within hours of its launch earlier on Nov. 18 and is being used to discover VNCs—remote PC connections—as a means of increasing its growth vector.
The eSafe CSRT (Content Security Response Team) at Aladdin—a security company—detected the new threat propagating around noon EST on Nov. 18. At 18:00 UTC (Coordinated Universal Time), eSafe had detected 1 operator and more than 500 on-command bots in the network. Less than three hours later, or by 2:30 EST, when eWEEK spoke with Ofer Elzam, eSafe director of product management, the number had soared to several thousand PCs and was growing by several hundred systems per hour. eSafe is monitoring the IRC channel used to control the botnet. The only inhabitants of the network besides the operator are in fact infected PCs. The Trojan is an IRC bot thats spreading through MSN Messenger by sending itself in a .zip file with two names. One of the names includes the word "pics" as a double extension executable—a name generally used by scanners and digital cameras: for example, DSC00432.jpg.exe. The Trojan is also contained in a .zip file with the name "images" as a .pif executable—for example, IMG34814.pif. The files are infiltrating new systems by using either known contacts from which the Trojan has harvested instant messaging names, as well as from the systems of unknown users. The infection vector—an IM program—isnt new. But the Trojan is the first that eSafe has tracked that has tried to scan for VNC (Virtual Network Computing) instances, likely in order to multiply the botnets number of connections. Elzam said that the Trojan shares common characteristics with other Trojans, looking like "a flexible Swiss Army knife" with multiple processes to steal passwords, to spread the infection and to deliver spam, for example. Are VM rootkits the next big threat? Click here to read more. Given the familiar social engineering aspect of the attack, individuals are being urged to not open files sent unexpectedly from either friends or strangers. eSafe hasnt determined what criminal activity the botnet is up to at this point. Editors Note: This story was updated to correct the erroneous interpretation that this Trojan was searching for VMs and to correct the name of Ofer Elzam. eWEEK regrets the errors. Check out eWEEK.coms Security Center for the latest security news, reviews and analysis. And for insights on security coverage around the Web, take a look at eWEEKs Security Watch blog.
Lisa Vaas is News Editor/Operations for and also serves as editor of the Database topic center. Since 1995, she has also been a Webcast news show anchorperson and a reporter covering the IT industry. She has focused on customer relationship management technology, IT salaries and careers, effects of the H1-B visa on the technology workforce, wireless technology, security, and, most recently, databases and the technologies that touch upon them. Her articles have appeared in eWEEK's print edition, on, and in the startup IT magazine PC Connection. Prior to becoming a journalist, Vaas experienced an array of eye-opening careers, including driving a cab in Boston, photographing cranky babies in shopping malls, selling cameras, typography and computer training. She stopped a hair short of finishing an M.A. in English at the University of Massachusetts in Boston. She earned a B.S. in Communications from Emerson College. She runs two open-mic reading series in Boston and currently keeps bees in her home in Mashpee, Mass.

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