No, they are trying to infect your mind with the urge to visit their websites and hopefully purchase something. To that end some of them are willing to put adware on your machine, and most of them just stick to spam and popups. Adware does assorted things. Sometimes it tracks where you go online and uploads that data (using the bandwidth you pay for) to gather neilsen-style statistics (information you don't get paid for). Sometimes it hijacks your web browser and gives you popups which, in turn, place a cokie on your machine to track how often you have seen their popups and clicked on them and so on. Sounds like you need to download and rune Ad-Aware, to me. That's probably where most outside 'attacks' or attempted handshakes are coming from.