avgnsa.exe is a program which is probably NOT a virus or malware. So, if avgnsa.exe is on your PC, it is probably ok, and will NOT be a cause for concern. Even if your system is virus-free, it is still recommended to use a well-known antivirus with a good detection rate, in order to defend your PC against threats.
This application is usually stored on disk in C:\Program Files (x86)\AVG\AVG2015\avgnsa.exe.
The MD5 checksum for this program is 71a01ebb6f9a7242e745e67b9a8f3845.
This program does NOT run as a Windows service. This is usually a good sign.
64-bit code has been detected. This program can put to good use the full power of a modern PC cpu.
The description written in the file is AVG Online Shield Service.
File version stored as a property 126.96.36.19901.
Producer AVG Technologies CZ, s.r.o..
Copyright notice Copyright (C) 2016 AVG Technologies CZ, s.r.o..
avgnsa.exe has a digital signature. Nowadays most serious software applications are digitally signed.
The digital signature extracted from avgnsa.exe checks out perfectly. This is very good.
Digitally signed by: AVG Technologies CZ, s.r.o.
Certificate's issuer name: VeriSign Class 3 Code Signing 2010 CA
It has an uninstall routine, which is good. si are uninstall.