What a busy day! Microsoft just released an advisory with details about a new vulnerability in Word, which is currently being exploited in targeted attacks.

Earlier today, we found a mention of such a vulnerability in an advisory published by Symantec. Symantec published this advisory based on a sample our handler Maarten sent to our malware distribution list. The file in question was actually part of a bundle of files he sent. As far as we know, this is the only sample we had which exploits this vulnerability.

Please read the Microsoft advisory carefully. According to Microsoft's testing, it only affects Microsoft Office Word 2002 Service Pack 3. This is one reason we didn't consider this particular sample as we didn't test it with this particular version of Office.

Needless to say, this is yet another reminder that exploits like this are likely to continue in targeted attacks. Feel free to send us suspect samples. Luckily, there is some anti-virus coverage in this particular case.

As a sidenote: Maarten will be talking about his work with these targeted exploits as SANSFIRE . Better register now !

The md5 hash of the particular sample we have: 0x7C0812F6207FF8E9FEF016DE48786168 (attachement.doc). Excerpt from Virustotal:

F-Secure 7.60.13501.0 2008.07.03 Trojan-Dropper.MSWord.Agent.cq
GData 2.0.7306.1023 2008.07.07 Trojan-Dropper.MSWord.Agent.cq
Kaspersky 7.0.0.125 2008.07.07 Trojan-Dr
Sophos 4.31.0 2008.07.07 Troj/MalDoc-Fam
Webwasher-Gateway 6.6.2 2008.07.07 Exploit.Win32.Ginwui.gen!MS-Word (suspicious)

Links:

Symantec: www.securityfocus.com/bid/30124/info

Microsoft Advisory: www.microsoft.com/technet/security/advisory/953635.mspx

Microsoft Blog Post: blogs.technet.com/msrc/archive/2008/07/08/ vulnerability-in-microsoft-word-could-allow-remote-code-execution.aspx