The fake antivirus exploit prompts for a download in IE, Opera, and Firefox because the download is an executable file for which these browsers prompt by default. I showed Opera in a previous post.
Ok, so there is a download prompt and you get a chance to cancel the whole thing, in those cases where it attempts to make you download an exe file instead of serving a browser or plugin exploit. That is good news.
The other exploits I found are automatically triggered (drive-by download):
IE exploits against the browser as I showed in the previous post.
PDF exploit in Firefox. This is from a previous exploit. Note that it is Acrobat calling out for the trojan and not Firefox:
Note that this is an Acrobat Reader exploit, not a browser exploit. The browser just loads the PDF file. This exploit works in all browsers. Be sure and configure your file types to Prompt for Download, or "Always Ask"
Ok, so the actual drive-by downloads (no user consent required) of this badware are based on exploits in either the browser or some other related program like PDF viewers, as usual. And the PDF exploits you can stop just by having the browser prompt for download of pdf files instead of opening them in the proper program, or even just by not giving the PDF viewer permission to go online when your firewall prompts for it. Good news, again!
Thanks for all the advice, guys, I think I understand how this thing operates now. If I got it right, this thing is not a threat as long as you
- have your browser set to prompt for download for exes, pdfs etc instead of having the browser run them at once, and cancel any suspicious, unwanted downloads, and
- have a fully patched browser that isn't vulnerable to the browser exploits this thing tries, such as the latest Opera version.
Or in other words, it's a pretty basic baddie. Sounds like I'm good to go, and have nothing to worry about this malware. It should be easy to avoid this thing: just keep the browser patched (and preferably use Opera) and have it set to prompt for downloading stuff, or disable all the pointless plugins we don't need like Adobe Reader etc.
Still, Foxnews should get their ads cleaned right the F now. It's inexcusable for a big outfit like that to serve crapware via ads. I wonder if a popup blocker would help against these things.