Cracks and keygens are known for carrying infections ( as well as being illegal).
If you downloaded Camtasia and any other programs via P2P file-sharing, they could also be infected. You antivirus software will not necessarily detect these problems, depending on what programs you're using and how up to date the definitions are.
Please follow the instructions
here (5 pages) and then post all the requested logs in a new thread
here for the security analysts to look at. If you have any trouble running any of the scans, leave them and move onto the next.
The security forum is always busy, so please be patient and you will receive a reply as soon as possible. If you go to Thread Tools > Subscribe at the top of your new thread you will receive an email as soon as a reply is posted.