If you recall using one or more of the pathetic passwords in the list below, we strongly recommend changing them now. Some of the most common passwords worldwide:. Those often include names of pets, lovers, pet-lovers, ex-pets, or something related to the actual service, like its name lowercase. As mentioned above, one of the first things to do when password cracking is getting the password in the form of a hash.
Then you create a table of common passwords and their hashed versions and check if the one you want to crack matches any entries. Experienced hackers usually have a rainbow table that also involves leaked and previously cracked passwords, making it more effective.
Most often, rainbow tables have all possible passwords that make them extremely huge , taking up hundreds of GBs. On the other hand, they make the actual attack faster because most of the data is already there and you only need to compare it with the targeted hash-password. Luckily, most users can protect themselves from such attacks with large salts and key stretching, especially when using both. If the salt is large enough, say bit, two users with the same password will have unique hashes.
This means that generating tables for all salts will take an astronomical amount of time. As for the key stretching, it increases the hashing time and limits the number of attempts that the attacker can make in given time. No password cracking starts without proper tools. When you have to guess from billions of combinations, some computational assistance is more than welcome. As always, each tool has its pros and cons. Here is a list, in no particular order, of the most popular password cracking tools.
Featured in many popular password cracking tools lists, John the Ripper is a free, open-source, command-based application. Word lists used in password cracking are on sale, but free options are available as well. This is a multi-purpose tool, capable of many different functions. If you already have the hash, this tool will offer a dictionary or brute force attack option. Ophcrack is a free and open-source password cracking tool that specializes in rainbow table attacks. As you can see in the screenshot above, it took Ophcrack merely six seconds to crack an 8-symbol password while using a rainbow table that includes letters, numbers, and uppercases.
Ophcrack is available on Windows, macOS, and Linux. Arguably the strongest point of THC Hydra is not the possible number of heads it can grow but the sheer number of protocols it supports that seems to be growing too! The methods available with THC Hydra include brute force and dictionary attacks while also using wordlists generated by other tools.
This password cracker is known for its speed thanks to the multi-threaded combination testing. It can even run checks on different protocols simultaneously. It offers a number of techniques, from simple brute force attack to hybrid mask with wordlist.
This makes cracking multiple hashes simultaneously much faster. But what makes this tool truly universal is the number of supported hash types. In fact, it supports over hash types. Hashcat dictionary attack Since humans tend to use really bad passwords, a dictionary attack is the first and obvious place to start. The rockyou. Many other free wordlists exist on the internet, especially targeted at specific languages.
Hashcat lets you specify the wordlist of your choice. Hashcat combinator attack Humans often create passwords that are two words mushed together. Hashcat exploits this using a combinator attack that takes two-word lists also known as "dictionaries" and creates a new word list of every word combined with every other word. The hashcat documentation gives the following example of two dictionaries:.
Punctuation such as hyphens - , exclamation points! Hashcat mask attack Lots of users tend to use passwords in a certain format. One uppercase letter followed by six letters plus a digit on the end is common for older passwords -- "Bananas1", for example. Instead of trying to brute-force every possible password, you can use hashcat to search for all passwords in that format, which drastically reduces the number of possible guesses necessary -- if, indeed, the password in question is in that format.
The hashcat documentation explains why a mask attack is often orders of magnitude faster than a brute-force attack:. Hashcat rule-based attack If other, easier, options fail, and you've got a specific sense of how your target constructs a password, hashcat offers a programming language-like syntax for a rule-based attack, in which you can specify what kind of passwords to try.
It can also be used to find hidden resources like directories, servlets and scripts. THC Hydra is an online password-cracking tool that attempts to determine user credentials via brute-force password guessing attack.
THC Hydra is extensible with the ability to easily install new modules. Download THC Hydra here. Medusa is an online password-cracking tool similar to THC Hydra. It claims to be a speedy parallel, modular and login brute-forcing tool.
Medusa is a command-line tool, so some level of command-line knowledge is necessary to use it. Password-cracking speed depends on network connectivity. On a local system, it can test 2, passwords per minute. Medusa also supports parallelized attacks. In addition to a wordlist of passwords to try, it is also possible to define a list of usernames or email addresses to test during an attack.
Read more about this here. Download Medusa here. All password-cracking is subject to a time-memory tradeoff. This threat is why passwords are now salted: adding a unique, random value to every password before hashing it means that the number of rainbow tables required is much larger. RainbowCrack is a password cracking tool designed to work using rainbow tables.
It is possible to generate custom rainbow tables or take advantage of preexisting ones downloaded from the internet. Download rainbow tables here. A few paid rainbow tables are also available, which you can buy from here. This tool is available for both Windows and Linux systems.
Download RainbowCrack here. OphCrack is a free rainbow table-based password cracking tool for Windows. It is the most popular Windows password cracking tool but can also be used on Linux and Mac systems. A live CD of OphCrack is also available to simplify the cracking. This tool is available for free. Download OphCrack here. Download free and premium rainbow tables for OphCrack here. L0phtCrack is an alternative to OphCrack.
It attempts to crack Windows passwords from hashes. For cracking passwords, it uses Windows workstations, network servers, primary domain controllers and Active Directory. It also uses dictionary and brute-force attacks for generating and guessing passwords.
It was acquired by Symantec and discontinued in Later, L0pht developers again reacquired it and launched L0phtCrack in L0phtCrack also comes with the ability to scan routine password security scans. One can set daily, weekly or monthly audits, and it will start scanning at the scheduled time.
Learn about L0phtCrack here. For example, people frequently use the names of children, addresses, phone numbers, sports teams and birthdays as passwords, either alone or in combination with other characters. People freely post personal information in their profiles or tweet repeatedly about the sports teams or celebrities they follow.
These are natural paths for a dictionary crack to pursue. Buy Now. For longer passwords, brute force and dictionary techniques may be combined to narrow the realm of possible combinations.
Some brute force cracking software also uses rainbow tables , which are lists of known codes that can sometimes be helpful in reverse-engineering encrypted text. How vulnerable are password files to brute force attacks? In the tech news site Ars Technica gave an editor who had no experience with password cracking a list of 16, encrypted passcodes and challenged him to break as many as possible. Within a few hours, he had deciphered nearly half of them. If some of the statistics cited above are intimidating, rest easy.
The laws of mathematics dictate that longer passwords are harder to break than short ones, and passwords that contain random combinations of characters are more secure than those that conform to a known pattern.
Unfortunately, few people can remember a random digit string of characters, much less multiple strings for different logins. Equally unfortunate — from a security perspective — is that computers are getting faster and cracking algorithms are getting better.
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