"Today Microsoft released a security advisory (961509) regarding collisions in MD5 hashes on certificates. This specific problem affects the entire industry and is not a Microsoft specific vulnerability. Serious weaknesses in MD5 have been known for many years now; it is because of these weaknesses that MD5 is banned in new code under the Microsoft Security Development Lifecycle (SDL). Software developers are urged to migrate away from using MD4, MD5 and even SHA1 and use SHA-256 and later instead for hashing, signatures and message authentication codes (see slide 22 for more information http://download.microsoft.com/download/8/4/7/8471a3cb-e4bf-442a-bba4-c0c907d598c5/Michael%20Howard%20SDL%20Development%20Practices.ppsx)"
For the rest of this story, check out:
at the Microsoft Security Vulnerability Research and Defense blog
Thomas W Shinder, M.D., MCSE
Sr. Consultant / Technical Writer