At first I thought this was a new exploit, then thought it was an old one, but now realise it is a new exploit. It seems that this was first discovered by Benjamin Tobias Franz several months ago, however it was only a DoS then. It appears he didn't disclose the flaw responsibly. However, Computer Terrorists figured out how to turn the DoS into code execution and made no additional effort to report the flaw to Microsoft. That's not cool. This does not free Microsoft of responsibility, they should have seen the DoS and fixed it six months ago, but they couldn't have seen this version coming.
Computer Terrorists, your actions will contribute to a rise is spyware and support the idiot criminals who make the internet a bad place. This is an obvious piece of glory hounding and you deserve to lose clients for your lack of ethics.
UPDATE: There's a snort signature. FrSIRT also has the sploit.
UPDATE II: The ISC just raised the InfoCon Threat Level to yellow.
UPDATE III: Microsoft has released an advisory.
1I don't want to contribute to their pagerank, I am sure you can figure out the proper link.

