/System/Library/PrivateFrameworks/AppSSO.framework/Support/AppSSOAgent.app/Contents/MacOS/AppSSOAgent Single Sign-on (SSO) process designed to enhance users' sign-in experience with apps and websites when using Apple devices. When you sign in with your password and other authentication information, SSO creates a ticket with it and validates the ticket for about 10 hours. During this time, a user no longer needs to enter the password again to access resources.
The binary is a part of AppSSOAgent application.