No, it does not, you need have the Malicious Software Removal Tool: http://www.microsoft.com/downloads/
details.aspx?FamilyID=AD724AE0-E72D-4F54-9AB3-75B8EB148356&displaylang=en
I have sp2 so blaster is not a threat, i was just wondering
whether on an xp without the necessary patches/service
pack/antivirus tools would MSAS notice anything or give a
warning or just silently let the worm come in?