Hi not sure where to ask this, so I pick here. While visiting my own site tonight I got a pop-up. Can't figure out how? I do not have any on my site. it was related to my business. Is this possible or was it just a late pop-up from past sites visited long ago. I had just gone online. This was the statement on the bottom of the pop up.
"The offers shown to you by SaveNow are not affiliated with the site you are visiting. For more about SaveNow, please click here or email email@example.com."
Do a site search for "adaware" to see many recent threads (and some dating back a year) on this problem. The most plausible answer to your avoidance question is to restrict ActiveX controls in your Internet Explorer security settings. One of the sites you visited was hosting the installer for this thing, so it downloaded itself into your machine.
The search above will give you lots of other ploys to beware of.
I think it's appropriate to call this stuff "scumware" and I hope the word gets out and the companies that allow it pay the price... disgusting behaviour, IMHO.