Hi Sarah, welcome to Tom's.
Every running process on Windows can be targeted by malware, that doesn't make the process itself a virus or any other form of malware.
As the name suggests, it helps with the login/logout processes on your PC. You don't need to tinker with it.
If you're worried that it's actually affected my rogueware, you can run
this file from Microsoft (Sysinternals.com) to check out if there are any rogue handles/dll running under the legitimate winlogon.exe.
What is it that makes you suspicious in the first place?
If you have a real time Antivirus program running on your system with a software firewall program, maybe you're alright.