Thunderbird Icon Name Changed on its own!

When I powered my computer up the other morning, I noticed that my Thunderbird Desktop Icon Label/Name had been changed. The strange thing is... the name under the icon was actually the beginning of my password that I use to log into my Thunderbird email. I have run all the appropriate scans and have found no malware, viruses, etc... What else would have caused this name change to occur? Should I be concerned that someone may have taken over my PC? I live alone and am the only person that uses the computer. I have done some digging on the Internet and cannot find anything on this topic. Please help... thank you.

 

Thanks for the info. I haven't changed the name back, although I know I can do that. Just found it strange that it happened to have changed to part of my Thunderbird password. I've had my computer hacked into once before, so I am probably more paranoid then most