Microsoft Security Essentials and Forefront Endpoint Protection today started reporting world wide the presence of Exploit:JS/Blacole.BW when accessing http://www.google.com, http://www.google.ca, http://www.google.com.au, and several others. Apparently blog sites were buzzing with concerns, and suspicions of a false positive. Despite the Microsoft malware description in the image below, it has ultimately been reported ( by Stephen Burns) as a false positive, and Microsoft hopes to release a definition update a short while after 2:00 am GMT, Feb 15/2012
UPDATE 2:30 am GMT:
Just received virus definition update # 1.119.1988.0 and seems to have resolved the problem on our systems..
LAN-Tech Network Management 
Comments on: "Security Essentials JS/Blacole.BW false positive" (1)
Great bllog