Share this story.In March, readers followed along as, Ars deputy editor and a self-admitted newbie to password cracking, downloaded a list of more than 16,000 cryptographically hashed passcodes. Within a few hours,. The moral of the story: if a reporter with zero training in the ancient art of password cracking can achieve such results, imagine what more seasoned attackers can do.Imagine no more. Hello kitty folder icons for mac. We asked three cracking experts to attack the same list Anderson targeted and recount the results in all their color and technical detail style.
The results, to say the least, were eye opening because they show how quickly even long passwords with letters, numbers, and symbols can be discovered.The list contained 16,449 passwords converted into hashes using the. Security-conscious websites never store passwords in plaintext. Instead, they work only with these so-called one-way hashes, which are incapable of being mathematically converted back into the letters, numbers, and symbols originally chosen by the user. In the event of a security breach that exposes the password data, an attacker still must painstakingly guess the plaintext for each hash—for instance, they must guess that '5f4dcc3b5aa7deb882cf99' and '7c6a180b36896a0a8c02787eeafb0e4c' are the MD5 hashes for 'password' and 'password1' respectively. (For more details on password hashing, see the earlier Ars feature '.' )While Anderson's 47-percent success rate is impressive, it's miniscule when compared to what real crackers can do, as Anderson himself made clear.
When you're creating a username or password for an online account. In a typical dictionary; any standard dictionary cracker can crack that password in less time. As blatantly obvious as that sounds, many people feel no compunction about. And don't forget to create a password-protected user account for yourself on. Hash Crack: Password Cracking Manual Picolet, Joshua on Amazon.com. Like myself, can't remember exact syntax of every tool, or the source of quality word. I feel this manual benefits beginners to intermediate pentesters best that have.
To prove the point, we gave them the same list and watched over their shoulders as they tore it to shreds. To put it mildly, they didn't disappoint.
Even the least successful cracker of our trio—who used the least amount of hardware, devoted only one hour, used a tiny word list, and conducted an interview throughout the process—was able to decipher 62 percent of the passwords. Our top cracker snagged 90 percent of them.The Ars password team included a developer of cracking software, a security consultant, and an anonymous cracker. The most thorough of the three cracks was carried out by, a password expert with. Using a commodity computer with a single, it took him 20 hours to crack 14,734 of the hashes, a 90-percent success rate. Jens Steube, the lead developer behind, achieved impressive results as well.
(oclHashcat-plus is the freely available password-cracking software both Anderson and all crackers in this article used.) Steube unscrambled 13,486 hashes (82 percent) in a little more than one hour, using a slightly more powerful machine that contained two. A third cracker who goes by the moniker radix deciphered 62 percent of the hashes using a computer with a single 7970 card—also in about one hour. And he probably would have cracked more had he not been peppered with questions throughout the exercise.The list of 'plains,' as many crackers refer to deciphered hashes, contains the usual list of commonly used passcodes that are found in virtually every breach involving consumer websites. '123456,' '1234567,' and 'password' are there, as is 'letmein,' 'Destiny21,' and 'pizzapizza.' Passwords of this ilk are hopelessly weak. Despite the additional tweaking, 'p@$$word,' '123456789j,' 'letmein1!,' and 'LETMEin3' are equally awful. But sprinkled among the overused and easily cracked passcodes in the leaked list are some that many readers might assume are relatively secure.
':LOL1313le' is in there, as are 'Coneyisland9/,' 'momof3g8kids,' '1368555av,' 'n3xtb1gth1ng,' 'qeadzcwrsfxv1331,' 'm27bufford,' 'J21.redskin,' 'Garrett1993.,' and 'Oscar+emmy2.' A screenshot showing a small sampling of cracked passwords.As big as the word lists that all three crackers in this article wielded—close to 1 billion strong in the case of Gosney and Steube—none of them contained 'Coneyisland9/,' 'momof3g8kids,' or the more than 10,000 other plains that were revealed with just a few hours of effort. So how did they do it? The short answer boils down to two variables: the website's unfortunate and irresponsible use of MD5 and the use of non-randomized passwords by the account holders.
Life in the fast lane'These are terrible passwords,' radix, who declined to give his real name, told Ars just a few minutes into run one of his hour-long cracking session. 'There's probably not a complexity requirement for them. The hashing alone being MD5 tells me that they really don't care about their passwords too much, so it's probably some pre-generated site.' Like SHA1, SHA3, and most other algorithms, MD5 was designed to convert plaintext into hashes, also known as 'message digests,' quickly and with a minimal amount of computation. That works in the favor of crackers.
Armed with a single graphics processor, they can cycle through more than eight billion password combinations each second when attacking 'fast' hashes. By contrast, algorithms specifically designed to protect passwords require significantly more time and computation.
For instance, the SHA512crypt function included by default in Mac OS X and most Unix-based operating systems passes text through 5,000 hashing iterations. This hurdle would limit the same one-GPU cracking system to slightly less than 2,000 guesses per second. Examples of other similarly 'slow' hashing algorithms include, scrypt, and.The other variable was the account holders' decision to use memorable words.
The characteristics that made 'momof3g8kids' and 'Oscar+emmy2' easy to remember are precisely the things that allowed them to be cracked. Their basic components—'mom,' 'kids,' 'oscar,' 'emmy,' and numbers—are a core part of even basic password-cracking lists. The increasing power of hardware and specialized software makes it trivial for crackers to combine these ingredients in literally billions of slightly different permutations.
Unless the user takes great care, passwords that are easy to remember are sitting ducks in the hands of crackers.What's more, like the other two crackers profiled in this article, radix didn't know where the password list was taken from, eliminating one of the key techniques crackers use when deciphering leaked hashes. 'If I knew the site, I would go there and find out what the requirements are,' he said.
The information would have allowed radix to craft custom rule sets targeted at the specific hashes he was trying to crack.