What is com.appstart.AppStart?
Seems fishy enough to investigate. It's either some custom software like java applet or other software that isn't the normal CodeSigned or app store installation.
- It's in the wrong location for apps to be typically
- Uses generic sounding names
- You're clearly not aware what it is or why it's there.
If you have Time Machine - you can do two things. Make a backup and then delete the file. Next, you can look in spotlight on the TimeMachine to see when it showed up and perhaps correlate it to other app installs. It could be a side app that does metrics or app updates - but I'd probably get rid of it or see what other files it has open or monitor where its talking with a tool like LittleSnitch. Malware Bytes anti malware is also very good and reputable product to scan for known adware, malware, scamware, etc...