Several keyloggers and fake virus scanners have legit professional and very deceptive looking sites, this does not mean they haven't installed themselves on your computer. They want to make it look legit so when you find it you go looking and throw money at them to either get it to go away or buy their service which is most likely never going to do anything for you.
Prime example "mycleanpc" they have TV commercials here to make them look legit, they are 110% a scam, it's a false virus scanner it tells you your computer is infected, or it's running slow because.... meanwhile nothing it detects is actually on your computer. Several of these same "virus scanning" softwares would install themselves if you went to nefarious websites without protection, they were a pain in the ass for someone who knows what they are doing to get rid of. This is the new form of virus. It's extortion.
Honestly, get rid of it and don't fret to much, If you're running windows Download and install Microsoft Security Essentials and keep it updated, you'll never have to worry about anything. Well other then the NSA and every other American agency but we all got to worry about that anyways
The last thing LEO would do is install a keylogger on your PC, especially one you could google lol
If they had a keylogger or some sort of monitoring software consumer grade antivirus' would not pick it up most likely, and if they did someone like Norton would be screaming from the rooftops to sell more copies of their product, they do it every single time a new virus is detected.
I'd be way more concerned about online banking and Credit card numbers then I would be about browsing growing forums. The filthy russians that steal this info don't give a shit what you're growing, they want to add your #'s to the list of thousands of other credit cards to sell in bulk.
Edit: I didn't even research it before I made this post, but of course it's the russians behind it
http://www.threatexpert.com/report.aspx?md5=d46de171172f8e8f1c74e7c4f78891c5