If it's anything, I'd blame the advertisement company. But I'm just pointing my fingers at them even though I don't know if they're at fault or not. I have had problems with some sites I've been sent to from the advertising agency, though. Hackers? Advertisement? False Alarm?
And no... I haven't seen that problem on my firefox browser.
I'm not entirely sure what the issue might be, but the warning seems to be only present when webpages are served from a specific server under poor network conditions (corrupt data causing a false positive perhaps?). While I investigate further, the services on that machine have been temporarily disabled.