The Cryptome.org whistleblowing website was hit by a serious web hijack last week that for several days borrowed thousands of its pages to serve malware, the organisation has admitted.

Starting on 8 February, attackers were able to hide malicious scripts pointing to malware on every one of the site’s 6,000 pages, leaving its admins battling to regain control until 13 February, Cryptome said.

The malware culprit was the Blackhole exploit kit 12, the latest version of a notorious but sadly incredibly common automated web compromise system designed to serve malware targeting specific browser versions with known software flaws.

Anyone visiting with a vulnerable browser (Internet Explorer 6 to 8) could have found themselves infected with Blackhole, most likely adding their computer to a larger bot.

“5,000 more files found infected, still checking, but it looks as though every HTML file on Cryptome was infected.” The organisation said.

“Not clear how access was gained through our ISP. Access logs do not show the infection activity. Any ideas how that was done and how to prevent recurrence: cryptome[at]earthlink.net.”

The involvement of the Russian Blackhole kit is absolutely standard, indeed a report last week from M86 Security pointed out that this one web exploit system is now so successful and powerful it accounted for 95 percent of all attacks using such kits in the second half of 2011.

As with the Cryptome attack, website owners only know they have a problem when users contact them with the bad news after detecting it with security software wise to its many techniques for staying out of sight.

For Blackhole, a site such as Cryptome is merely a convenient jumping off point that allows it to serve malware via a legitimate domain that won’t be blacklisted by security software or search engines.

In this attack, the criminals appear to have gone to some trouble to keep the malware out of sight for as long as possible by ignoring anyone visiting the site from a Google domain. Presumably this was done to reduce the chance of Google’s search engine blacklisting Cryptome, a security layer incorporated into Chrome through the Safe Browsing API.

Overshadowed by Wikileaks in terms of publicity, Cryptome has had a few brushes with controversy.

Two years ago, the organisation published Microsoft's secret Global Criminal Compliance handbook, which laid out how the company was gathering certain data from users of some of its services that could be accessed by the police and intelligence services.

Angry at the guide's publication, Microsoft had the Cryptome website suspended using legal sanctions, before relenting as negative publicity accumulated on the Internet.

Later in 2010, an attacker broke into Cryptome's servers, stealing a reported 6.8 terabytes of data including emails written by the site's founder, John Young.