The Web site for the U.S. Consulate in Russia was hacked into earlier this week, infecting pages with malware that would attack visitors.

Researchers at security company Sophos told InformationWeek that the consulate's IT team cleaned up the infection within a matter of days. They also reported that the break in was part of a widespread attack that resulted in more than 400 Web pages around the world being infected over the last week by what appears to be the same hacker group.

"If an organization like that can be hacked into, it's pretty discouraging to other organizations and businesses," said Graham Cluley, senior technology consultant with Sophos. "We don't think this was a targeted attack against the consulate. The hackers just got lucky that the site was vulnerable."

Sophos researchers discovered the data breach while investigating a piece of malware that a customer nearly picked up at the consulate's Web site. Cluley said they didn't work with the consulate on the break in or the malware because the site was being cleaned up by the time they discovered it.

The U.S. Consulate didn't have any information about the breach up on its Web site and a call for information was not returned.

By retrieving a copy of one of the infected consulate pages from an Internet cache, Sophos researchers found that the hackers had planted a downloader generally known as Mal/ObfJS-C into the page. If the malware infected a user's computer, it is designed to pull down other malicious code. Part of the download includes a malicious script that attempts to exploit several browser vulnerabilities in order to install a Trojan horse that could be used to steal business critical data and personal details.

It's not known how many visitors to the Web site might have been infected.

"This latest attack highlights the fact that no organization is immune from infection, and that no matter what the size of the company, it must defend its Web pages fully to avoid being stung," said Fraser Howard, principal virus researcher at SophosLabs, in a written statement. "The hackers have reeled in a big fish on this occasion and will no doubt be very pleased with their catch of the day. Unfortunately, while high-profile sites, such as the U.S. consulate, can be cleaned up quickly, we are seeing a dangerous number of companies that are failing to act responsibly to retain the sanctity of their sites."