Obfuscators are also classified as code modifiers which change the structure of the code while retaining the flow of the program. In the previous chapter, we introduced the control flow flattening (CFF) technique. The CFF technique converts a small code to run in a loop which gets controlled by a control flag. However, obfuscation is not limited to the CFF technique. The compiled file structure can also be modified, especially for a psuedocode based execution, like Visual Basic  and .NET compiled programs.

One of the main techniques to obfuscate is to garble, or encrypt, the name of functions so that decompilers wouldn't be able to recognize the function correctly. Examples of these high-level obfuscating tools are Obfuscar, CryptoObfuscator and Dotfuscator.

The renaming of variable names with random generated text strings, converting the code text to hexadecimal text, and splitting text for the code to concatenate the text are some obfuscation techniques used for scripts such as JavaScript and visual basic scripts.

The following screenshot gives an example of an obfuscated JavaScript code using an online obfuscation tool:

The original code is at the left while its obfuscated version is at the right.