marți, 20 noiembrie 2007

Trojan horse spreads quickly through Microsoft's IM

Compromises 11,000 PCs in first 24 hours, says researcher
A new Trojan horse that started to spread early Sunday via Microsoft Corp.'s instant messaging client has already infected about 11,000 PCs, a security company said today.

The as-yet-unnamed Trojan horse began hitting systems about 7 a.m. EST on Sunday, according to Roei Lichtman, the director of product management at Aladdin Knowledge Systems Ltd. "We still haven't found what it's meant to do, but at the moment, it's creating an army [of bots]," he said. "Eventually, of course, the operator will send commands to do something."

Users of Microsoft's Windows Live Messenger instant messaging program receive a message that includes spoofed Zip files, such as one named "pics" that is actually a double-extension executable in the format "filenamejpg.exe" or a file labeled "images" that in reality is a .pif executable.

"This is really growing rapidly," said Lichtman. Six hours after it first found the Trojan horse, Aladdin put the total number of assembled bots at about 500; three hours later, that had climbed to several thousand. By late today, the botnet had been built out to 12,000 machines.

As with other malware spread through instant messaging software, the messages bearing malicious code appear to come from people on the recipient's IM contact list.

But while its speed in spreading is impressive, Lichtman pointed to another characteristic of the Trojan horse: It can also propagate via virtual network computing (VNC) clients, the generic term for remote control programs used to access one computer's files and desktop from another.

Once the Trojan horse has installed itself on a PC through IM, it can sniff out a VNC client, then use it to infect a remotely controlled system, perhaps one inside a corporation's firewall. "You increase your reach to these PCs as well, as if you infected them," Lichtman said, momentarily taking the hacker's point of view. To his knowledge, the Trojan's use of a VNC vector was a first.

Aladdin will continue to monitor the bot's spread by tapping into the Internet Relay Chat channel being used to command and control the compromised PCs, said Lichtman.

IM-based threats, while still relatively rare compared with those that spread via e-mail or from malicious Web sites, aren't unknown. Neither are vulnerabilities within IM software. In September, for example, Microsoft forced users of its aged MSN Messenger software to upgrade to Windows Live Messenger 8.1 to stymie a vulnerability in the older program.

Hackers poised for Black Friday assault

You know retailers are ready for Black Friday -- but so are hackers poised to launch a slew of Web-based attacks against consumers. Your money and personal information could be at risk.

"The holiday season in general is a huge time for hackers ... [and] Black Friday is typically the start," says Paul Henry, vice president of strategic accounts for Secure Computing. "This year, my biggest concern for consumers is all the Web-borne malware out there."

Black Friday, the day after Thanksgiving, is followed in marketing lingo by Cyber Monday. Both are big days for retailers and online fraudsters. Consumers should watch out for e-mails advertising incredible deals that seem too good to be true. "Freebies may be freebies in the sense that you get free malware," says Jamz Yaneza, a senior threat researcher at Trend Micro.

A common scam is to pick the hot toy of the season and send out a spam e-mail blast offering it for much less than the typical price, Henry says. Victims end up entering credit card information on malicious sites designed to look like well-known, trusted ones. They might also unknowingly download a keylogger that can steal personal information people type in when making any kind of Internet transaction.

"Be leery of sites being advertised [in e-mail that might be spam]. In all likelihood you're being directed to a malware-connected site," Henry says. "Do not click on URLs within e-mails even for well-known public sites."

In an HTML e-mail, it's a trivial task for hackers to hide the real URL a victim is clicking on.

"It might say ',' but you're actually clicking on something entirely different," Henry says.

Online fraudsters have been busy this year. Fraud losses related to U.S. e-commerce will top $3.6 billion in 2007, up 20% from last year, according to a report by the vendor CyberSource this month. The increase in dollar loss is due mostly to growing e-commerce sales, as the percentage of transactions that are fraudulent has held steady.

The run-up to Christmas and tax filing season are the two most dangerous times of the year for online shoppers, Yaneza says.

In addition to being wary of e-mails, be careful when searching for holiday deals or specific products on Google and other search engines. Operators of malicious sites have figured out ways to rise to the top of search listings.

"We've seen instances where the top site that is ranked actually gets there by gaming the Google search algorithm," Yaneza says.

Legitimate Web sites can be dangerous too, when hackers inject code into Web pages redirecting users to malicious sites, Yaneza says. The Dolphin Stadium Web site was attacked in this way prior to this year's Super Bowl in Miami.

Black Friday and Cyber Monday will be a bigger problem for consumers than enterprises, according to Henry, because large businesses tend to have better security. But that doesn't mean there's nothing for IT executives to be leery of.

Cyber Monday is thought to be a big day for online retailers because people return to work en masse after the Thanksgiving break and are sitting in front of office computers all day.

Businesses might also worry about employees using work laptops in unprotected Wi-Fi locations, and getting targeted with a keylogger or other malicious software, says Yaneza.

Yaneza's advice for consumers is simple but often effective: Install all the latest updates and patches for your security software and Web browsers.

Trend Micro offers a free tool called HouseCall that can scan your computer for viruses, spyware and other malware.

Hackers jack, infect job hunters took a portion of its Web site offline Monday as researchers reported that it had been compromised by an IFrame attack and was being used to infect visitors with a multi-exploit attack kit.

According to Internet records, the Russian Business Network (RBN) hacker network may be involved.

Parts of the Monster Company Boulevard, which lets job hunters search for positions by company, were unavailable Monday; by evening, the entire section was dark. Most major American companies are represented on the site -- Google Inc.'s cache of the page that shows only those firms that begin with the letter B, for example, included Banana Republic, Bank of America, Black & Decker, Boeing, Broadcom and Budget Car Rental.

Job seekers who used Monster's by-company directory on Monday before the site was yanked were pounced on by Neosploit, an attack tool kit similar to the better-known Mpack, said Roger Thompson, chief technology officer at Exploit Prevention Labs Inc.

"A typical infective URL was, which is Toyota [Financial's] section]," said Thompson in an instant message exchange Monday night. "Or, which is Best Buy's."

The injection of the malicious IFrame code into the site probably happened Monday, he added. "It was interesting that we got five or so hits in the space of a few hours today, but none before that. I think it happened today."

Like many other IFrame exploits, this one silently redirected the user's browser to another site hosting Neosploit. In the case of at least one of the exploit sites Thompson identified, there's a connection to the notorious RBN, the hacker and malware hosting network that recently shifted operations to China, then mysteriously abandoned the IP blocks it had acquired in China, seemingly vanishing from the Internet.

The IP address of the exploit site is assigned to a server in Australia that is part of the "" domain. That domain, in turn, is registered to a Hong Kong Internet service provider called HostFresh Internet. Both HostFresh and have been linked to RBN activities, including the long-running IFrame Cash scheme, in which RBN pays small site owners a commission for injecting IFrame exploits on other sites.

According to an anonymous blogger who tracks the RBN, other IP addresses were involved in the Bank of India hack in August.

Thompson said he had just started digging into the hack on Monday afternoon. "It is not clear how many pages were affected, but it is likely that the attack was the same for all companies on the site, which might turn out to be a pretty good set of the Fortune 500," he said on his blog.

Maynard, Mass.-based last made security news in August, when the company acknowledged that hackers had looted its database for weeks, perhaps months, then used that information to craft and send targeted e-mails that pitched money laundering jobs or tried to trick recipients into downloading malware. was not available for comment Monday night.