Details of hijacked 24/7 ad server emerge

Ground control to major mess

Tripod places ads on sites hosted under its free plan; customers who pay hosting fees, however, do not have ads stuck on their sites' pages.

It's not known if the only sites served with ads containing the IFrame were Tripod's. There were hints, however, that Tripod might not be the only tainted domain. Last Wednesday, for example, NASA issued a warning to workers of a surge in attacks on Windows PCs running Internet Explorer and RealPlayer. According to the space agency's bulletin, the attacks had come from "well-known news sites which may be hosting advertisements from ad servers that redirect the users to malware hosting sites." Friday, NASA spokesman Mike Mewhinney declined to name the news sites the agency suspected of displaying rogue ads.

Because 24/7 Real Media's ad research is significant, the IFrame-infected ads may have been placed on a large number of Web sites. According to the most recent data from Internet audience measurement firm comScore, 24/7's ads reached 50% of all Americans online last month. The company's reach placed it at No. 15 on comScore's September Top 50.

24/7 Real Media did not respond to e-mails sent Friday and Sunday.

Symantec couldn't pin down the start date of the attack, but it did note that the malicious site had hosted exploit code since at least Oct. 8. "There is a possibility that this IP [has been] controlled by the same attackers for quite some time and that they are using it to launch numerous low-key attacks," said Adams, Ball and Roe.

Late Friday, RealNetworks issued a patch for RealPlayer 10.5 and the RealPlayer 11 beta. It also urged users of earlier versions to first upgrade to 10.5 or 11, then apply the patch. Only Windows versions of RealPlayer are vulnerable, RealNetworks said in its advisory; Mac and Linux versions are not at risk.