There are a few recent how-to-get-started threads on here. Take a look around, someone may have already provided the answers you need.
A few notes:
Cryptography is not about programming viruses. Cryptography is about making and breaking codes. If you want to learn about Cryptography, check out Applied Cryptography by Bruce Schneier or Understanding Cryptography by Chrisof Paar and Jan Pelzl.
If you want to know more about viruses, check out Malware by Ed Skoudis and Lenny Zeltser or The Art of Computer Virus Research and Defense by Peter Szor.
If you want to learn about penetration testing, check out the recent threads and/or read Counter Hack by Ed Skoudis or Hacking Exposed by McClure et. al.
Penetration testers are not licensed, at least in the U.S. I haven't heard of it anywhere else either, but...maybe things are different in Myanamar or somewhere. I don't know.
For an online class, maybe check out eLearn Security? http://www.elearnsecurity.com/course/penetration_testing/