A hacker tool can be any tool used by a person to gain illegitimate control over a user's computer. A hacker tool could be used to break in or installed on the victim's computer and used to maintain control. Hacker tools include:
- Network sniffers - Although used by administrators to prevent security violations, a network sniffer may be used by an attacker to gain access to information not intended for them.
- Port scanners - Port scanners are used to test computers to determine whether they are running specific services. They may also indicate the operating system being used on a computer system. Once a port scanner establishes the characteristics of a computer system including the services that are running, an attacker then will be able to probe each service for any vulnerabilities to gain control of the computer system.
- Keyloggers - Keyloggers may either hardware or software and may be installed on a computer to record every key typed. If the keylogger is software it may not be able to get a windows password, but if the keylogger is hardware plugged in between the keyboard and computer, it can record all passwords entered. A hardware keylogger must be accessed directly by the attacker so physical access to the computer is required but they can be difficult for users to detect. A software keylogger may be able to send keystrokes to the attacker remotely anywhere on the internet. Firewalls that filter network traffic going out to the internet may help prevent the keylogger traffic from getting to an attacker.
- Password cracking tool - There are many password cracking tools that are made to obtain passwords from encrypted passwords or even hashed passwords. Some tools will use a dictionary attack which assumes the password is a dictionary word or a variant of it and uses the dictionary words to guess the password, then hash or encrypt it, and finally compare the created value with the stolen value. A password cracking tool may use brute force attack to try all possible combinations of characters for a password until a match is found. Password cracking tools may use both dictionary attack, brute force attack methods and other methods to break passwords.
There are also many custom hacker tools that skilled hackers will write for themselves and others. They may be generic tools or written to work against a specific vulnerability on a particular operating system or service. If these hacker tools are released to the public, want-to-be hackers with very little computer skill can use them to hack computer systems.