Creating malware
A backdoor is a file that gives full control over the machine (Windows, Linux, macOS) that it gets executed on.
Backdoors can be caught by antivirus programs.
A keylogger is a program that records keys pressed on the keyboard.
Runs in the background of target system.
Reports every key pressed on the target machine to email.
Starts with system boot, hence can be caught by antivirus programs.
A password recovery tool can be used as a post exploitation tool to retrieve saved passwords on local computer. It needs to be executed on target computer and displays logs on screen or stores them in a local file. Find one that:
Recovers saved passwords from lots of programs.
Recovers passwords from memory.
Works with Windows and Linux.
Displays result on screen or stores it on local machine.
A trojan presents itself as a useful legitimate program so that users could get fascinated by it and install it. It usually tricks users by using social engineering techniques. For example:
Download backdoor + keylogger.
Download keylogger + password recovery tool.
Download keylogger + password recover tool + backdoor.
Use it as a trojan – evil file + a normal file.
Attack tree
1 Create payload (AND)
1.1 Backdoor
1.2 Keylogger
1.3 Password recovery tool
1.4 Trojan
1.5 ...
4 Download to & execute payloads on target machine