Nowadays writing exploits and software to assist in spreading malicious code can be a very lucrative business.
It's something out of a Mario Puzo novel, interpreted by Neal Stephenson. Criminals, presumably operating out of Russia, hire qualified programmers to create exploits for recently patched vulnerabilities not just in Microsoft Windows, but in applications such as Apple QuickTime as well. The criminals then sell this package of exploits as a tool to others who then install the necessary code on servers around the world.