A packer is a software tool used to compress, encrypt, and obfuscate executable files in order to make their analysis and reverse engineering more difficult.
Packers are often used by legitimate developers to protect their programs from unauthorized copying and modification. However, this same technology is also actively exploited by attackers to conceal malicious code from antiviruses and other security tools.
The principle behind a packer is that it takes the original executable file, compresses and/or encrypts its contents, and then adds a special unpacking code to be executed at runtime. As a result, the packed program becomes a kind of “Russian doll,” where the original code is hidden under several layers of protection.
For cybersecurity specialists, it is crucial to be able to analyze packed files in order to identify potential threats. This is done using specialized tools such as unpackers, debuggers, disassemblers, and other reverse engineering techniques.
