Posted by Virus Bulletin on Mar 30, 2007
Trojans sneaking in through animated cursor flaw.
A vulnerability has been discovered in the handling of .ani files, used for animated cursors on web pages and in HTML emails, and has been spotted as a proof-of-concept exploit on malware writers' discussion boards and in use for attacks.
The exploit involves maliciously crafted .ani files, implanted on web pages or spammed via email, and can be used to silently install trojans on victim machines. After an initial blog posting from McAfee (here), exploitation of the flaw has been reported by numerous sources and Microsoft has issued an initial security advisory. Users of most current versions of Windows, including Windows Vista, are thought to be affected, although the exploit may not work on Windows XP without Service Pack 2, and the Firefox 2 and Internet Explorer 7 browsers are also thought to be protected from the flaw.
Users are advised to allow only plain-text email, although this may not protect users of the popular Outlook Express, or the Windows Live Mail program included with Vista. Administrators may want to consider blocking .ani files at the gateway. Microsoft's advisory is here, while an update to McAfee's blog posting is here and some analysis of an exploit from Trend Micro is here. An alert from the SANS Internet Storm Centre can be found here, and another from Secunia, labelled 'extremely critical', is here.
Posted on 30 March 2007 by Virus Bulletin
