Time between vulnerability disclosure and worm spread has been drastically reduced.
The MS08-067 vulnerability has been published some hours ago. Microsoft rated this vulnerability as critical, as a remote unauthenticated attacker could exploit it to execute arbitrary code in the vulnerable host.
This vulnerability is caused due to a bug in the Windows Server service handling a crafted RPC request.
The vulnerability affects almost all the Windows operating systems family, with some differences. On Windows 2000, XP and 2003 an attacker could exploit this vulnerability without the need of a username and password. However, the exploitation in Windows Vista and Windows Server 2008 requires a valid username and password.
The really interesting thing about all of this is that Microsoft published the following in its Security Bulleting:
It is possible that this vulnerability could be used in the crafting of a wormable exploit.
The name of the worm is Gimmiv.A and uses this vulnerability to spread over the network. On infection, the worm injects two DLLs into the services.exe address space. After that, the worm retrieves information from the compromised host (including passwords from the Windows protected storage) and posts it in encrypted form to a remote host.
The worm posts the details to a number of hosts, including http://perlbody.t35.com/
At the time of writing the host is up and running and contains details of 3779 hosts stored int the http://perlbody.t35.com/icon.txt file.
The worm also downloads the following image stored on the http://perlbody.t35.com/ server:
Microsoft and SECFORCE recommends that customers apply the update immediately as other versions of worms exploiting this vulnerability are likely to be released.