Friend Request advertisers?

For the last week, I've been getting 3-7 friend requests every single time I log in (Daily). Upon accepting the request, an instant chat box window pops up with an advertisement for a specific website or something else LoL related.

Its not like its a hassle to decline 3-7 friend requests daily, but its a hassle to rationalize whether my account is compromised in some way or not, given that someone, or something, is giving out my summoners name for advertisers to blow up.

The only third aprty program/website I use is LolNexus to do some research on stats for players on the opposing team during 'game load', and thats it.

This is not a big deal, but im a tad bit concerned, and Im wondering if anyone else is having the same problem.