macT

Hello, I recently had an unsettling experience. I went to log into hotmail, but there was already an E-mail address in the field where I would put my own. It was not an E-mail address that I use, nor does anyone else have (direct) access to my computer. I did realize that I had left my firewall off for sometime, and had recently also been enticed into clicking a less than secure link from a web page. I'm not usually that gullible, but... It happened. So, my question is - How could this E-mail have shown up? Is this some kind of malware, or something more serious such as someone having access to my computer? I have since re-established all my security. I do have a wireless home network, but it is a secure connection. There was also a brief time where I was trying to access a public, unsecured network, but didn't SEEM to have any luck. Any insight would be appreciated!