At the moment, the number of different WMF exploits we’ve seen has gotten well past a hundred and more are coming every hour.
But that’s not the worst. The most recent exploits show that the bad guys have been very very busy finding and implementing new ways to get their exploits past various AV products. So much for the dark side taking a break over the winter holidays and New Year.
Not surprisingly, we haven’t taken a break either. We released an update to our heuristics which deals not only with the most recent exploits but also with a few tricky ways to exploit the vulnerability which haven’t been used in attacks – yet. Just as a precaution, you know.
At the same time, some people, Microsoft included, are busy develping fixes. Our friends from F-Secure have blogged about Ilfak Guilfanov’s patch, which is currently the most popular one.
A beta version of the Microsoft patch, scheduled to be released on January 10, was leaked on the Internet. Microsoft has recommended customers to “disregard” it, warning that threats could be hidden in any patches coming from dubious sources.
Of course, you should never use a patch from an untrusted source, no matter how promising it looks. Ilfak’s patch is the only one we can recommend. Make sure you do some testing beforehand, especially if you are going to deploy it on a large number of production machines though. Ilfak, who is the author of the popular IDA disassembler, knows what he’s doing, and the work he’s put into developing the patch is admirable.
And finally, you should always be very wary of any third party patch from an untrusted source, whether it’s claiming to fix an old vulnerability or the latest WMF vulnerability. This is a method which has successfully been used in the past to distribute malware.