Last modified: 2010-06-13 13:39:56 UTC
"js/crasher" is alerting McAfee VSE 8.7i when the "crasher squirrel" wiki page is loaded in MSIE. The VSE attempts to delete the js/crasher, but the delete fails. (http://en.wikipedia.org/wiki/Crasher_Squirrel)
Sounds like a bug in mcafee being to overzealous looking for evil js, since there is no evil js in that page.
Not a bug in MediaWiki, just an overzealous antivirus. If the problem persists with up-to-date virus defnitions, please report to McAfee.