Files such as this, with just slightly altered names of legit files are a common method used by Trojans. They use an extra letter, or a capital instead of the legit files lower case (svchost legit, svcHost not legit, etc.). You can upload any of these suspect files to
Virus Total A fake file will not have the correct md5 sum, and it will not say the file has already been scanned, but instead will make a new scan.
I think you are safe to rename, and eventually delete, but you want to make sure you are no longer infected. Emails being sent is another telltale sign of infection. Often sending an attached file to spread the infection, or even spam if your system has been taken over by a bot.
Scanning with a bootable AV disk is suggested, as it runs outside of windows, and will not let these files load. A rootkit scan would also be wise
Panda Anti-Rootkit - Free software downloads and software reviews - CNET Download.com
for instance is free, and does run fine on my x64 Home Premium.
A Guy