As one zero day gets patched, (Microsoft released an out-of-cycle patch for the recent VML Fill vulnerability) another is found.

Today we discovered an exploit affecting Microsoft PowerPoint (preliminary testing shows Office 2000, Office XP, and Office 2003 are affected). A single target of this exploit has been identified, so like other recent Microsoft Office 0-day discoveries, it appears that this one is also a targeted attack.

What makes this attack interesting, is the fact that it appears that Microsoft’s antivirus product added detection three days ago. The only public information on these threats is the boiler plate Malicious Software Encyclopedia entries (which show an incorrect discovery date of Sep 26, when virus definition files from Sep 23 detect):

There isn’t a public advisory from Microsoft; suggesting the Microsoft’s security team knew of this in-the-wild attack but did not make the information public.

For the record, I am not a fan of full disclosure (the concept, not explicitly the mailing list). I believe that more money has been lost, more data stolen, and more illegal activity around exploits has happened because of full disclosure. Historically, those with the skills to find vulnerabilities and create exploits are not the ones who write Blaster and Sasser, etc. Generally, the people who heavily abuse exploit code have “copy & pasted” the work of others. They customize the payload and release, and in these cases damages would have been significantly reduced if it were not for the availability of exploit details.

That said, if an attack is in the wild, acknowledgment of the attack is not something to conceal. Non-disclose the nitty-gritty details, but do inform.

- Update Sep 27, 2006 9:30 -
Correction, coverage went into the 4861 DAT release.

- Update Sep 26, 2006 17:00 -
McAfee antivirus coverage for these two exploits was released earlier today in DAT version 4860; detected as Exploit-PPT.d trojan.