Part of macOS
sshd…Remote Login
○ Leave it
Lets people sign in to this Mac over the network with SSH.
What it is
Runs when Remote Login is on in Sharing settings.
If you stop it
Anyone signed in is disconnected. Turn it off in System Settings › General › Sharing instead.
The verdict
○ Leave it. Part of macOS, or something that starts again by itself. You never need to close these.
In Activity Monitor
sshd…
… means any name that starts this way.
From Procession’s guide, in the words the app shows.