Reverse engineering

When you don't have the source code, or when the source code is intentionally obfuscated, you must reverse engineer a system in order to understand how it works.

A lot of time, this is related to understanding malware.

There are many conferences and industry groups related to hacking and security e.g. Blackhat, DefCon, RSA, IEEE Security & Privacy, NDSS, USENIX Security, ACM CCS, etc. where reverse engineering is a main focus of discussion.

Here are some links to the topic:

1. https://reverseengineering.stackexchange.com/questions/4561/how-to-deobfuscate-an-obfuscated-javascript-file-like-this
2. https://isc.sans.edu/diary/Advanced+obfuscated+JavaScript+analysis/4246