Malware writers have used a Wikipedia article and special storage features to attempt to plant malicious code on unsuspecting users' systems, the online encyclopedia's organizers have confirmed.

The incident took advantage of Wikipedia's policy of openness, which allows anyone to create and modify articles. The attackers created a Wikipedia page that promised a Windows security update for a supposedly new version of the Lovesan/W32.Blaster worm, and pointed to an external site with the seemingly authentic domain wikipedia-download.org.

Wikipedia editors quickly identified and deleted the article, according to a report from German news organization Heise. However, the attackers had used a Wikipedia feature that archives all previous versions of articles when changes have been made.

The malicious page thus continued to exist in the archive, and the attackers were able to point to it in mass e-mails, according to Heise.

The e-mails used Wikipedia's logo, and explained that Microsoft had asked Wikipedia to assist with hosting the patch during a supposed Lovesan/W32.Blaster outbreak.

Wikipedia confirmed it has now deleted the archived versions of the malicious article. Wikipedia-download.org also leads to a dead end.

In August, Wikipedia co-founder Jimmy Wales, addressing the Wikimania conference, acknowledged growing problems for the encyclopedia around accuracy and malicious edits, and promised to improve quality. The English version of Wikipedia passed 1 million entries this year.