JOHN THE RIPPER DICTIONARY ATTACK PASSWORD
System administrators should use John to perform internal password audits.
JOHN THE RIPPER DICTIONARY ATTACK CRACK
One of the tools hackers use to crack recovered password hash files from compromised systems is John the Ripper (John). As one of their first passes at cracking a password hash, they’ll use a regular expression attack with the name of the company. Hackers are too smart for such low-level trickery as using company name permutations for passwords. Similarly, users also wouldn’t want to select a password by simply reversing the company name to RalKram2563
This is a weak password because it’s easily guessed by a hacker attempting to break into The Marklar Company. It is a strong password for someone who isn’t employed at The Marklar Company at 2563 Snarkish Way. , you might conclude that this is a strong password. System administrators need to audit passwords periodically, not only to make sure they comply with password policies, but to ensure that those that do aren’t simple enough to be guessed by an outsider.įor example, if a user chooses to use the password MarklarCo2563 Time is important when cracking passwords because the hacker knows that once the victim discovers the compromise, new security measures and password changes rapidly go into effect. With a powerful computer and enough time, no password can escape the hacker’s relentless attack. A hacker can recover dictionary-based passwords in minutes, whereas a brute force attack can take days.īrute force is a single-character-at-a-time attack on a password file. Dictionary-based passwords make the hackers life easy, and the return on investment for checking a password hash file against a password dictionary is very high.
Hackers know that most users will opt for simple, dictionary-type passwords. To decrease the amount of time taken to crack passwords, hackers will first try dictionary word matches. Once the hacker collects a system’s password files, he can now take advantage of password attack options at his disposal. This procedure allows the hacker to crack the passwords at his leisure and in the safety of his own computer lab. The hacker will save a system’s password and shadow files to a remote location. “No” because an intruder who has attained administrative access can use some powerful tools to crack the passwords on your system. It’s then up to the administrator to investigate the matter.
This lockout triggers intruder detection alerts and notifies system administrators that something suspicious has happened. Random password guesses result in account lockout after a limited number of incorrect attempts. “Yes” because complex passwords prevent a hacker from guessing your password either across the network or locally on a system. The question is, “Is all that complexity enough to protect us from hackers?” The answer, to further complicate matters, is “Yes” and “No.” And, we’re discouraged from using the same password for every account. Password policies designed by well-meaning system administrators dictate the required number of characters and the complexity of passwords, but is that dictated complexity enough to protect user accounts from hackers? We’re told to create passwords that are “easy to remember but hard to guess.” We’re instructed to choose passwords that contain upper- and lowercase letters, that include numbers, and that have a few alternative characters as well.