Obfuscation
Disguising of program code or spam messages
Obfuscation is a technique used in both malware and spam, to disguise the content of a malicious program or of a spammed message.
In programming, the obfuscation of code to hinder reverse engineering and code changes has legitimate uses, to protect copyrights and intellectual property. In malware creation, it is generally intended to make the process of analysing the malware more difficult and time consuming. Any programming language, including both compiled and scripting languages, can be obfuscated, making it difficult to read or follow the logic and structure of the program.
In spam, obfuscation is intended to defeat automated rather than human readers. Words commonly used in spam, such as the names of popular proprietary drugs, are hidden in a way which makes it unclear to anti-spam software, but when displayed the words are easily recognisable to a human eye. The insertion of spacing, interspersal of letters with nonsense code or invisible characters, or use of patterns of colour and size are among many techniques used to create such obfuscation.
