Inspired somewhat by the Department of Homeland Security Threat Advisory Level (or was it the other way around?), Symantec maintains a global threat level called ThreatCon, defined as “a measurement of the global threat exposure, delivered as part of Symantec DeepSight Threat Management System.”
On Tuesday, Symantec elevated ThreatCon to a level 3 (out of 4) out of concern for the potential threats from the WMF vulnerability in Windows.
For some perspective, this is the first time ThreatCon has been this high since July 2004 for MyDoom.M, when it actually hit the maximum level of 4 (which I think indicates Global Thermonuclear War). Prior to that it had reached 3 in May 2004 for Sasser.
Needless to say, ThreatCon at level 3 is not a common occurrence, and I agree its been a while since we had a really serious threat on our hands. Its also fair to say that Symantec is extremely concerned about the WMF vulnerability, in spite of the fact that they havent identified any actual attacks of any importance.
Theres logic to this, since they fear that even if everyone can protect themselves, and even if users with updated anti-virus are protected (a controversial hypothesis, but assume it for the sake of argument), there are still large numbers of systems that are completely unprotected.
Microsoft uses a number that 50 percent of systems out there dont have updated anti-virus protection, and most outside observers think that 50 percent is an optimistic number.
Symantec isnt alone. Perhaps the most influential piece of writing in the gloom and doom school of this particular problem was this diary entry by Tom Liston of the Internet Storm Center. “Ive written more than a few diaries, and Ive often been silly or said funny things, but now, Im being as straightforward and honest as I can possibly be: the Microsoft WMF vulnerability is bad. It is very, very bad.“
Actually, now that Microsoft has announced they are releasing the update early I bet Symantec downgrades. But of course, theres also some large percentage of users who dont apply updates, and theyll still be vulnerable. Its not over yet.
Not an Elite Threat
I was very concerned at first too, but it always seemed to me that this was not in the “elite” level of vulnerabilities.
Those are reserved for network worms, the most famous of which were Blaster and Sasser.
These are attacks that can exploit a remote computer purely by sending commands and data to it over the network. These are the attacks you can suffer just by installing a new copy of Windows and putting the machine on the Internet to get updates.
The WMF flaw suffers by comparison to these problems. No computers can be attacked without the user actually clicking on a link or opening an attachment.
There are many other mitigating factors, although the one I just mentioned really is the most important. And the fact that a patch has now been issued definitely ratchets down the threat level.
At least I think it should, but I was one of the ones who never thought it was a first-class emergency anyway, and Im not alone either, although I get the feeling Im in the minority.
Neither, it appears, did Microsoft. Im sure they released the patch today mostly to preempt the third-party patches that were appearing and because of the anxiety out there, not because of the actual level of threat.
The reason for regular monthly patch days is to let IT plan for updates and do them on a regular schedule, so its only worth going out of cycle when the threat is really urgent or when IT is so worried that they want it anyway.
In this case I think the hysterical press this subject got put enough customer pressure on Microsoft that it was worth going out of cycle, after it was worth “accidentally” leaking a copy of the patch a couple of days ago.
So what explains the difference in opinions? Of course Im a partisan here, so theres a limit to how objective I can be, but I see a couple of factors.
One is a dispute over how many users are dumb enough to open attachments in messages from strangers on an unprotected computer, or click links in them.
My contention is that almost anyone who could get hit by this probably has already had their computer compromised by adware or some other form of malware.
Nothing is added to the malware “ecosystem” by compromising these machines with the WMF flaw; theyre already owned.
Ive had a theory for years that the systems being infected with all the more prominent worms were being serially infected with all of them.
Its not hard to see why, either because of the suckers who own the computers opening every attachment that comes their way or outsiders using the backdoors to install new malware.
But there are large, very large numbers of computers that never get any of these attacks and barely ever see the messages with them, because they are properly protected. Its easy and not too expensive to do so.
And with every day that passes, I feel more comfortable with my outlook.
I must say though that Im surprised we never even see a moderately widespread attack. Its over a week now since proofs of concept were available, and still all I see are experiments.
Last weekend the consensus was that when everyone came back to their computers after the holiday, they were heading in like lambs to the slaughter. Malicious WMFs would spread backdoors and pornography throughout the Internet.
The way I see it, the WMF vulnerability is perhaps slightly worse than a bad mail worm episode, and its been a long time since any of them were serious problems. The recent Sober attack was serious, but hardly a crisis.
We havent had a really bad one since that MyDoom.M episode I mentioned earlier, and that one got all the attention only because of large numbers of submissions; thats not the same thing necessarily as large numbers of infections.
The longer we go without the sky falling, the more likely it is to stay up.
Security Center Editor Larry Seltzer has worked in and written about the computer industry since 1983. He can be reached at email@example.com.