Code obfuscation is one of the cornerstones of malware. The harder code is to analyze the longer attackers can fly below the radar and hide the full capabilities of their creations. Code obfuscation techniques are very old and take many many forms from source code modifications, opcode...
This is part one in a series of posts that focus on understanding Visual Basic 6.0 (VB6) code, and the tactics and techniques both malware authors and researchers use around it.