Hacking For Dummies® 3rd Edition

Chapter 7. Passwords

In This Chapter

• Identifying password vulnerabilities

• Examining password-hacking tools and techniques

• Hacking operating system passwords

• Hacking password-protected files

• Protecting your systems from password hacking

Password hacking is one of the easiest and most common ways attackers obtain unauthorized computer or network access. Although strong passwords — ideally, longer and stronger passphrases that are difficult to crack (or guess) — are easy to create and maintain, network administrators and users often neglect this. Therefore, passwords are one of the weakest links in the information security chain. Passwords rely on secrecy. After a password is compromised, its original owner isn't the only person who can access the system with it. That's when accountability goes out the window and bad things start happening.

External attackers and malicious insiders have many ways to obtain passwords. They can glean passwords simply by asking for them or by looking over the shoulders (shoulder surfing) of users while they type them. Hackers can also obtain passwords from local computers by using password-cracking software. To obtain passwords from across a network, attackers can use remote cracking utilities, keyloggers, or network analyzers.

This chapter demonstrates how easily the bad guys can gather password information from your network and computer systems. I outline common password vulnerabilities and describe countermeasures to help prevent these vulnerabilities from ...