Wow. This worm is fascinating. It seems to do the following: - Inject itself into the MediaWiki:Common.js page to persist globally, and into the User:Common.js page to do the same as a fallback - Uses jQuery to hide UI elements that would reveal the infection - Vandalizes 20 random articles with a 5000px wide image and another XSS script from basemetrika.ru - If an admin is infected, it will use the Special:Nuke page…
Note while this looks like its trying to trigger an xss, what its doing is ineffective, so basemetrika.ru would never get loaded (even ignoring that the domain doesnt exist)