The IT security industry creates annual revenues of maybe 50 billion $ per year worldwide. Israel is famous for it's hack on Iranian nuclear centrifuges, and it's firewall software ironically called CheckPoint Firewall-1. In Palestine, you have a few non-profit hacker groups such as KDMS-team.
Many business models of IT security require you to be close to your customers, but some business models can operate perfectly from remote, for example discovering and selling exploits.
The Business of Software VulnerabilitiesWell described in a recent Economist article, discovering a software vulnerability, or exploit, can be worth between 40.000$ and 500.000$ each.
You need a reputable IT security company, and you can offer your services to governmental agencies around the world. On the technical level, you will have software engineers, that are well familiar with IP networks and the use of common debugging and exploit tools.
Even normal software companies, lacking staff with specific hacking skills, can develop their own backdoors into their software, and create additional added value by hiding them well and selling them to governments.
This book can provide some beginner's tutorial on software vulnerabilities:
19 deadly sins of software security
Get Visual Studio that lets you view the memory.
Also you can analyse client-server interaction, and may find good ways to intercept them.
Or this video on reverse engineering: