The rtvscan.exe file runs the real-time scanning feature of the Symantec Internet Security Suite and is responsible for detecting malicious code embedded on possible viruses and other malware processes. When a file enters the system, the rtvscan.exe file will automatically execute and scan the file, immediately notifying the user about any files it detects. The rtvscan.exe file can also automatically clean the infected file.

For the full protection of your computer, the file rtvscan.exe runs continuously in order to check every file that enters your system. Aside from scanning and notifying the user about virus infections, it also logs or saves a report every time it performs a scan. The log or report details the information about the file scanned, its location, and the virus that came bundled with the file along with the actions taken by both the user and the program about the security risk.
Non-system processes like rtvscan.exe originate from software you installed on your system. Since most applications store data on your hard disk and in your system's registry, it is likely that your computer has suffered fragmentation and accumulated invalid entries which can affect your PC's performance.

In Windows Task Manager, you can see what CPU, memory, disk and network utilization is causing the Symantec Real Time Virus Scan service process. To access the Task Manager, hold down the Ctrl + Shift + Esc keys at the same time. These three buttons are located on the far left of your keyboard.

This process is considered safe. It is unlikely to pose any harm to your system. The rtvscan.exe file should be located in the folder C:\Program Files\symantec antivirus\. Otherwise it could be a Trojan.

This process is not considered CPU intensive. However, running too many processes on your system may affect your PC’s performance. To reduce system overload, you can use the Microsoft System Configuration Utility (MSConfig) or the Windows Task Manager to manually find and disable processes that launch upon start-up.

Use the Windows Resource Monitor to find out which processes and applications write/read the most on the hard drive, send the most data to the Internet, or use the most memory. To access the Resource Monitor, press the key combination Windows key + R and then enter 'resmon'.