How can i create anti virus program by c++ language

Answer 1

You need a list of hashes of lots of malware and hook a lot of functions in different windows dlls to perform heuristic analyses of the currently running programs. So you need to know at least
c/c++, assembly, .net runtime, have to be familiar with Reverse Engineering, need to have a way to get all the malware to analyse, automate most of that analysis, and have in depth knowledge of the windows kernel. On other operating systems it’s similar, but you can‘t just hook the windows dlls there but need to be creative

Answer 2

Well, at least you must know how every piece of PC hardware works, know computer architecture, processor, memory e.t.c., have pro skills in Assembler and C/C++. So you should know a lot.