Security+ Chapter 4 Password Attacks

Password related attacks

Brute-Force, Password Spraying, and Dictionary Attacks

Brute-Force Attack

iterate through passwords until they find one that works.

simply a process that involves trying different variations until it succeeds.

What do brute force attacks involve

word lists that use common passwords, words specifically picked as likely to be used by the target, and modification rules to help account for complexity rules.

Spraying Attack

form of brute-force attack that attempts to use a single password or small set of passwords against many accounts..

When is a spraying attack useful

effective if you know that a target uses a specific default password or a set of passwords.

Example of Spraying attack

if you were going to attack a sports team's fan website, common chants for the fans, names of well-known players, and other common terms related to the team

Dictionary Attack

another form of brute-force attack that uses a list of words for their attempts.

Tools for dictionary attacks

John the ripper(an open source password cracking tool)

Differentiator of attack methods

whether they occur online, and thus against a live system that may have defenses in place, or if they are offline against a compromised or captured password store.

Tool used when you can capture hashed passwords from a password store

Rainbow Table

Rainbow Tables

searchable database of precomputed hashes using the same hashing methodology as the captured password file.

How Rainbow Tables are used

if you captured a set of passwords that were hashed using MD5, you could compute or even purchase a full set of passwords for most reasonable password lengths, and then simply look up the hashes of those passwords in the table.

Hash

is a one-way cryptographic function that takes an input and generates a unique and repeatable output from that input.

Password Cracker

attempt to crack passwords by trying brute-force and dictionary attacks against a variety of common password storage formats.

John The Ripper Link

Learning how to use tools like John the Ripper can help you understand both password cracking and how passwords are stored. You can find a variety of exercises at

openwall.info/wiki/john/tutorials

How can password cracker tools be used for good

Password cracking tools like John the Ripper can also be used as password assessment tools. Some organizations continue to periodically test for weak and easily cracked passwords by using a password cracker on their password stores.

What do attackers or pen testers go for in a system that is not well maintained

Plain-text or unencrypted Passwords

What ways to protect passwords

using a strong password hashing mechanism, as well as techniques like using a salt and a pepper.

Best Practices rely on passwords never being stored and instead using a well-constructed password hash to verify passwords at login.

Securing Password Storage Link

cheatsheetseries.owasp.org/cheatsheets/Password_Storage_Cheat_Sheet.html.