Exploits Emerge for Microsoft Vulnerability

Security researchers have spotted the first attacks designed to exploit the critical vulnerability exposed in Microsoft Windows last week.

The vulnerabilities emerged as part of Microsoft's MS06-040 security patch, rolled out last Tuesday. (See Microsoft's Big Patch Day.) However, these initial exploits take the form of a low-risk botnet, rather than the damaging worm that many experts still expect.

The botnet, which has been called Cuebot-L, Graweg, and Mocbot, spreads like a worm via AOL Instant Messenger. Once it infects a PC, it turns off the Windows firewall and opens a back door, allowing remote attackers to gain access and control, according to researchers at SophosLabs.

Researchers at LURHQ Corp., a Chicago security management firm that has studied the botnet/worm, say there are two variants of the worm so far. The code is actually a modified version of an exploit that was written last year to take advantage of Microsoft's MS05-039 PNP vulnerability, they say.

The botnet is a relatively low-level threat and is remedied by the Microsoft patch, the researchers say.

Security experts continue to hunt for other, more dangerous attacks that exploit the MS06-040 vulnerability, which is considered to be a real danger because it provides a relatively easy way to gain remote access to PCs and laptops. (See How to Protect Against the MS06-040 Attack.) HD Moore, co-creator of the Metasploit Framework, publicly released his exploit on Thursday, and Symantec confirmed that Moore's code results in a denial-of-service attack.

— Tim Wilson, Site Editor, Dark Reading