Earlier today, I was browsing Daily Kos, and happened to the diary Dick Morris: Obama Blew It. No sooner did the article load than the various GOTV ads on the top and the side of the page were replaced with pornographic ads. Not just ads for pornography; the ads themselves were x-rated--including plenty of dick and plenty of blowing. (I suspect the keywords triggered the ads to appear; not all DKos pages featured this sort of stuff).
Another user reported a similar problem on Friday.
I don't visit porno websites, so I certainly don't expect banner ads for that sort of stuff (and such material would be highly inappropriate for Daily Kos regardless). After verifying that the browser history was clean (I do have young boys who might get curious) Did a little detective work and was able to clean up the problem.
As suspected, DKos is not the culprit--nor does it appear to be a specific target. I went to the webpage on Dick Morris's site linked to by the above article--and the suckage of his prose was likewise augmented by sucking of a different sort. I did some other experimentation--my Linux box was unaffected; just the Win7 box, and only Firefox. (IE didn't have the problem). Two different virus checkers were unable to identify the problem (AVG and SuperAntiSpyware). Finally, I found the culprit: a malware Firefox plugin called PlayBryte, which is supplied by an online gaming website of the same name (one my kids likely happened onto). Removing the plugin (both from Firefox's plugin manager and from Windows 7 Add/Remove Programs) seems to solve the problem.
More information about this particular malware can be found here.
If you haven't been infected by this, then don't worry about it. But if you are seeing x-rated advertising on Daily Kos (or anywhere else that you don't expect it)--it's not the site that's at fault; this particular malware just might be the cause.