Net Faces New Attack

A major Internet attack was under way last week, using malicious code to infect Web sites, and the servers and PCs that visit those sites. Several Web administrators from major companies said their Windows-based Web servers were compromised despite being up to date on security patches, security analysts report.

Web surfers are at risk of having their machines infected with Trojan horse applications, used to hijack computers, as well as keystroke loggers, which are capable of stealing personal information such as financial account numbers and passwords, security experts say.

Internet Explorer users who visited compromised Web sites were getting infected by a variety of vulnerabilities in the browser. There was no patch available for one of them, commonly known as ADODB, as of last week.

Daniel Frasnelli, manager of the technical assistance center for managed-security- services provider NetSec Inc., says the attack hit big E-commerce sites, including a major auction site, an auto-pricing site, and search-engine sites. "We all know these sites," he says, although he wouldn't provide names.

It wasn't clear how the attackers compromised the sites. "It'll take some considerable forensic examinations," says Alfred Huger, senior director of engineering for Symantec Corp.

Security experts were unclear about the motive behind the attack. Some say it can be traced to a Russian Web IP address of known spammers; others say it's designed to steal consumers' financial information.

Web surfers who visit affected sites are infected via Web-site objects that have malicious JavaScript code attached to them. The JavaScript then in the background contacts another Web site that inserts malicious software on the Web surfer's system.

Microsoft was investigating the attack and issued a statement saying some customers running unprotected versions of Internet Information Services 5.0, a component of Windows 2000 Server, were being targeted. Microsoft also urged customers to install the latest patches for Internet Explorer and to "utilize high security settings."

Most major antivirus firms have updated their antivirus software to spot and clean up computer systems infected with the back doors and keystroke loggers.