liz_marcs: Jeff and Annie in Trobed's bathroom during Remedial Chaos Theory (Default)
liz_marcs ([personal profile] liz_marcs) wrote2006-01-02 02:12 pm

Why Windows Sucks...Worm/Virus Warning: WMF Vulnerability

I heard/read about this a few days ago (I forget where) and only just now got around to looking into it.

Windows users ranging from 98 all the way up to present-day incarnations are vulnerable to this attack, although a patch for it has recently emerged.

Malware programmers exploiting a flaw in Windows programming can open Internet-connected machines to spyware, viruses, and other malware. All you have to do is view an image from either a Web site or in the preview pane of email to become infected.

All people using Internet Explorer are especially vulnerable. Users (like me) who use Firefox or Opera to get around Explorer's weaknesses are also vulnerable, although in some cases (by no means all) you'll be asked to download something to view the image with the malicious software encoded in it.

Please keep in mind, it appears you do not have to download anything to your computer. You just have to view the image to become infected.

It appears that Microsoft will not be sending out a fix until at least January 10. By then, we'll have a mess on our hands.

What makes this insidious is that the average computer user is vulnerable, even the paranoid sorts like myself who download almost nothing down to my computer unless it's from a trusted site.

The Washington Post more fully explains the details here and here.


Right now, the advice to deal with this is as follows:


  • Make sure that your Data Execution Protection (DEP) program is enabled. It helps block things somewhat, but it's not 100% certain to do so. There's some technical reasons why it's not a complete protection, something to do with hardware vs. software DEP. Still, it's a good idea to make sure it's on. If you want to check to make sure it's on:

    • Go into "Control Panel"
    • Click on "Performance and Maintenance"
    • Click on "System"
    • Click on the "Advanced" tab
    • Under the "Performance" option, click on "Settings"
    • Click on the "Data Execution Protection" tab
    • Make sure the second radial button is on
    • Click "OK"


  • Download a hotpatch that's been proven to work from here. Several security experts have vouchsafed for it. I downloaded it and installed it and have not seen any problems with my machine since I've done it.

  • Security Fix from the Washington Post offers another workaround that can provide additional protection. Once an official Microsoft patch is available, you can reverse this fix. Apparantly you might have problems seeing some images, especially thumbnail images, but I haven't had any problems at all since using this hack.

  • After you take the above steps, make sure to restart your machine to ensure your changes take hold. Before restarting, you may still be vulnerable, even if you've set DEP, downloaded the patch, and have used the hack.

  • If you download email to your computer, shut off the preview pane. Do not open email from unfamiliar addresses. One of the scams being used to deliver the virus is to the unsuspecting is notification that you've received a "greeting card" and to view it, you need to click on a link.

  • Before clicking on a link, hover your mouse over the link first and read the link that should appear at the bottom of your browser. If you see it takes you to an executable file, do not click the link.

  • Keep up with your Microsoft Security Updates. Although the "official" patch has not been made available, it's still good practice to do so. Again, we're looking at 10 to 14 days before we see anything out of Gates's people.

  • Keep your virus definitions and firewall updated. Some of the anti-virus companies have started working on solutions to root out problems. I know that Norton has already upgraded its firewall to help block it.

  • Do not visit visit Websites that are unknown to you. View even those Websites that are known to you with suspicion.

  • Download spyware detectors and keep them updated. I right now run three on a regular basis. I personally like Ad-Aware the best. I also use SpyBot and Microsoft Beta. Between the three, I'm kept pretty much spyware- and adware-free


Thankfully, I've been so busy this week that I haven't really done a lot of online research. End result, my machine is clean at least.

ETA: According to the Sunbelt Blog, chatting by IM will also make you vulnerable to this attack. Be sure to read through the latest posts, which gives a fantastic overview of the situation.

Also, check out the blog of the programmer who created the patch at Hexblog for updates on the patch as well as a nifty tool to see if you've vulnerable to attack. Please be aware that Hexblog is getting slammed right now as people race to get the downloads and fixes, so please be patient.

ETA2: SANS — Internet Storm Center has a .WMF FAQ on why this issue is so important.

ETA3: The latest Firewall Update from Norton/Symantec will not allow you to run the WMF Vulnerability Checker. It recognizes it as a virus/trojan/attack and jumps all over it before killing it dead before you can run it. Updated Norton Firewall also will not allow you to download any file name that includes "WMF" and ".exe" in it. Which, well, good because that's why I pay these people. On the other hand...

So please note that you should download the Hexblog patch before updating your firewall, otherwise you might be blocked from doing so.

ETA4: In light of the current WMF threat, and because my Norton Firewall threw up a WMF Exploit warning when I visited a YouSendIt link, I've gone through all the links included on my Sunnydale Survivors soundtrack to make sure they're "clean." The sites and downloads appear to be in the clear. However, this is subject to change as both YouSendIt and MegaUpload rotate ads. Please make sure to update your firewall protection (if Symantec has updated for WMF, I'm certain other firewalls have as well) before downloading any of the files.

[identity profile] smashsc.livejournal.com 2006-01-02 08:34 pm (UTC)(link)
other suggestions, in Firefox, under options, content, you can unclick Load Images and no images of any sort will load, or you can choose to only load images originating from the website you are viewing (safer on the theory that the malware is being stored on a seperate server from the evil pages).

Also, if you do not download the unoffical patch, make sure your windows is set to automatically download & install critical & security updates as soon as Microsoft releases them. I'm almost positive you can change this setting via the main windows update page: http://update.microsoft.com I know you can verify your setting on that page. If you are good it should say "Automatic Updates:
Turned ON." in a box top right.

[identity profile] liz-marcs.livejournal.com 2006-01-02 08:37 pm (UTC)(link)
Oh, I already have everything on automatic update, but it's surprising how many people don't.

Like I said, it appears my machine is clean, mostly because I haven't been doing a lot of browsing in the past week or two for research.

[identity profile] liz-marcs.livejournal.com 2006-01-02 09:11 pm (UTC)(link)
I just checked with the SANS site and they say shutting off images may help, but isn't a sure-fire guarantee against infection. Apparantly, the WMF extention can be embedded in all kinds of objects/documents.

Plus, if you use IM or IRC, that also adds to your vulnerability.

[identity profile] smashsc.livejournal.com 2006-01-02 09:26 pm (UTC)(link)
I know turning off images isn't a guarantee but it is something else that may help, as well as making sure WMF files aren't associated with any download autorun in Firefox. Options, Downloads, Download Actions, View & Edit Actions.

My computer is clean too. And I've got everything installed. Going above and beyond for protection is never a bad thing.

[identity profile] ad-kay.livejournal.com 2006-01-02 08:41 pm (UTC)(link)
Thanks for the info!

[identity profile] liz-marcs.livejournal.com 2006-01-02 08:55 pm (UTC)(link)
No problems.

Like I said, my computer feels like a fortress at the moment, and I'm still not done running through all my security programs.

[identity profile] a2zmom.livejournal.com 2006-01-02 09:02 pm (UTC)(link)
Thanks so much for the heads up.

[identity profile] liz-marcs.livejournal.com 2006-01-02 09:09 pm (UTC)(link)
When you've got security experts going ape across several high-profile sites, it's probably a good idea to listen.

A lot of the steps they're recommending is simple enough for me to follow the instructions, so it should be easy enough to do.

The only thing is I can't get through to Hex to download the new tool that allows you to check your system for vulnerabilities. I think I got in under the wire with the patch before the site went absolutely ape with everyone trying to DL from there. I'm sure there are mirrors around, but I haven't found any yet.

[identity profile] liz-marcs.livejournal.com 2006-01-02 09:29 pm (UTC)(link)
*starts laughing hysterically*

Thanks for the DL, but you're not going to believe what my Norton Firewall did when it hit the site.

It shut down the connection because it detected a WMF exploit on it. Now I can't download anything from that URL. I'll have to restart my computer before trying again.

In the meantime, I better check all my other links for my soundtrack to make sure they don't have the WMF exploits attached to them.

[identity profile] faithhopetricks.livejournal.com 2006-01-03 01:16 am (UTC)(link)
Thank you so much for posting this....I've been seeing dribs and drabs about it all day, but now we have the hotpatch, DEP is working, I've told FF to load images only from originating sites and we already have Windoze configured for automatic updates at all times. Maybe we've dodged the bullet. I can't believe there's not going to be an official patch til the 10th! That's just nuts.

[identity profile] rachelmap.livejournal.com 2006-01-03 02:58 am (UTC)(link)
Sigh. When are Microsoft going to provide even merely adequate levels of service and security?

[identity profile] aceliwen.livejournal.com 2006-01-03 04:33 am (UTC)(link)
Actually, the SANS Storm Center has a copy of the Hexblog patch on the page you already have linked. Same file name and everything. So that was a happy and immediate download...

[identity profile] iyalode.livejournal.com 2006-01-03 11:13 am (UTC)(link)
Got snookered by this on Boxing Day. Cost us $75 to get it fixed. Not happy! So thanks muchly for the info.

[identity profile] anelith.livejournal.com 2006-01-03 02:39 pm (UTC)(link)
Thanks for the tips! We've done what you advised regarding Control Panel and downloading the patch. Now to wait for Microsoft...

*tapping foot*