CEH Certified Ethical Hacker (312-50v9)

Fingerprinting an Operating System helps a cracker because:

In the context of Windows Security, what is a 'null' user?

What does the following command in netcat do? nc -l -u -p55555 < /etc/passwd

What hacking attack is challenge/response authentication used to prevent?

In this attack, a victim receives an e-mail claiming from PayPal stating that their account has been disabled and confirmation is required before activation. Th...