vsmon.exe is a process associated with the ZoneAlarm firewall. It is used to monitor Internet traffic and generate alerts depending on the security rules configured by the user. This program is important for the stable and secure running of your computer and should not be terminated.
Non-system processes like vsmon.exe originate from software you installed on your system. Since most applications store data in your system's registry, it is likely that over time your registry suffers fragmentation and accumulates invalid entries which can affect your PC's performance. It is recommended that you check your registry to identify slowdown issues