Recently there's been some concern around SBNation, people being redirected to a site that tries to get them to download something potentially malicious.
If you get these warnings, which appear as clearly bogus virus warnings, try and grab a screen shot. If that's not an option, just close the browser and email Support@SBNation.com, answering the following questions:
What browser/OS are you using?
What site were you on?
What page were you on?
When day did you first see this?
How many times have you seen it since?
Has it happened on any other sites? Which ones?
Did you click on anything after it redirected you to the virus scan screen?
Also, the product team would like to do a "screen share" session with you if this has happened to you; in your email let them know a time when you would be available to have such a session with them. The product team here has been working on eradicating this problem, and you can help. This last part is totally optional.
Anyhow, sorry for any worries or inconvenience this may have caused you.
[UPDATE] The issue causing this appears to have been identified; however, investigations are still going on. If you should receive a virus warning, please do follow the above instructions.