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8-Character Windows NTLM Passwords Can Be Cracked In Under 2.5 Hours (theregister.co.uk)
HashCat, an open-source password recovery tool, can now crack an eight-character Windows NTLM password hash in less than 2.5 hours. "Current password cracking benchmarks show that the minimum eight character password, no matter how complex, can be cracked in less than 2.5 hours" using a hardware rig that utilizes eight Nvidia GTX 2080Ti GPUs, explained a hacker who goes by the pseudonym Tinker on Twitter in a DM conversation with The Register. "The eight character password is dead." From the report: It's dead at least in the context of hacking attacks on organizations that rely on Windows and Active Directory. NTLM is an old Microsoft authentication protocol that has since been replaced with Kerberos. According to Tinker, it's still used for storing Windows passwords locally or in the NTDS.dit file in Active Directory Domain Controllers. It's dead at least in the context of hacking attacks on organizations that rely on Windows and Active Directory. NTLM is an old Microsoft authentication protocol that has since been replaced with Kerberos. Tinker estimates that buying the GPU power described would require about $10,000; others have claimed the necessary computer power to crack an eight-character NTLM password hash can be rented in Amazon's cloud for just $25.
NIST's latest guidelines say passwords should be at least eight characters long. Some online service providers don't even demand that much. When security researcher Troy Hunt examined the minimum password lengths at various websites last year, he found that while Google, Microsoft and Yahoo set the bar at eight, Facebook, LinkedIn and Twitter only required six. Tinker said the eight character password was used as a benchmark because it's what many organizations recommend as the minimum password length and many corporate IT policies reflect that guidance. So how long is long enough to sleep soundly until the next technical advance changes everything? Tinker recommends a random five-word passphrase, something along the lines of the four-word example popularized by online comic XKCD, "correcthorsebatterystaple." That or whatever maximum length random password via a password management app, with two-factor authentication enabled in either case.
NIST's latest guidelines say passwords should be at least eight characters long. Some online service providers don't even demand that much. When security researcher Troy Hunt examined the minimum password lengths at various websites last year, he found that while Google, Microsoft and Yahoo set the bar at eight, Facebook, LinkedIn and Twitter only required six. Tinker said the eight character password was used as a benchmark because it's what many organizations recommend as the minimum password length and many corporate IT policies reflect that guidance. So how long is long enough to sleep soundly until the next technical advance changes everything? Tinker recommends a random five-word passphrase, something along the lines of the four-word example popularized by online comic XKCD, "correcthorsebatterystaple." That or whatever maximum length random password via a password management app, with two-factor authentication enabled in either case.
Instead of 1 2 3 4 5, it will now be 1 2 3 4 5 6 7 8 9 0
You're confusing the scenario. This is not about brute forcing a login form.
This is about having the hashed password saved in the domain controller (for example from a DB stolen in other ways) and forcing the password hashes there to get all the passwords in the DB.
Even NTLMv2 is now over 20 years old. It's unsalted, easily parallelizable and you can't adjust the number of hash operations performed. It just can't deal with the modern world. And Microsoft has had tools available for like 5 years now that make it possible to see whether you can disable NTLM, see https://johan.grotherus.com/20... for one writeup. If you have a decently sized environment, this probably won't be easy, but you should start sooner rather than later. As soon as you are able to pull the plug on it, a lot of the easy "pass the hash" attacks become impossible, and those are more dangerous than someone getting to your ntds.dit file in todays age of gratuitous hard disk encryption anyway.
And most people aren't able to create secure passphrases. You need to use completely independant words to actually get a good passphrase, and if someone doesn't understand the information entropy theory behind it, they'll automatically gravitate towards related words. And a passphrase like "housegardengreengrass" has an absolutely abominable complexity of like 20000 * 100 * 100 * 100 or 2^32.
Couple of questions:
It wasn't entirely clear from the summary /s
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Note to author: It was determined during WWII that repeating plaintext makes it far easier for an opponent to crack the cyphertext. Just sayin'.
I have a datacenter full of Hashcat rigs - used to be my crypto mine but I re-purposed and now do fee-based password recovery for corporate and law enforcement clients.
Hashcat is pretty fun and has a scripting language of sorts for narrowing the attack space. If you have knowledge of the corporate password rules you're dealing with (which SIGNIFICANTLY reduce the attack space) it's actually not uncommon to discover even a complex password in a couple of days.
The bottom line is that everyone needs to use stronger passwords, and corporations really need to remove the impediments that reduce attack space.
As an example, let's take a simple example where a keyboard has all the capital and lowercase letters, and numbers 0 through 9. There are 52 possible letters and 10 possible numbers - 62 potential characters. An 8 character password has 62^8 or 218,340,105,584,896 possible combinations.
If I impose a rule that says you must have at least one capital letter, that more than halves the attack space because one combination drops from 62 possibilities to 26, and our new attack space is only 91,561,979,761,408.
If I say you have to have one capital letter and one number, that reduces a combination from 62 to 10, and our new space is only 14,768,061,251,840 passwords.
A GTX 1070 will do a Kerberos 5 password at about 145 million per second, so a single rack of 12 of them will do 1,740,000,000 passwords/second.
That means I can crack 8 characters, one capital letter and one number in a MAXIMUM of 8487 seconds, and that's assuming the correct password is the last one I try. That's less than 2.5 hours.
I have 200 of those racks in my farm, so it takes me longer to set up the job that it takes to completely exhaust that address space: 42 seconds.
So please, corporate America, keep right on with your silly password rules. They only make my job easier and more lucrative.
>"NIST's latest guidelines say passwords should be at least eight characters long. Some online service providers don't even demand that much."
The example given is an old method and assumes the cracker has access to the stored encrypted password. Then the discussion turns to a wide/broad generalization about ALL password lengths, and web sites were the example. This isn't logical. An 8 character password is way strong enough if you don't have access to the stored data and all you can do is try brute force- which is easily defeated by throwing in delays or limits.
It also depends on the method used to store the passwords, even if you have access to the stored data,
Tinker recommends a random five-word passphrase, something along the lines of the four-word example popularized by online comic XKCD, "correcthorsebatterystaple." That or whatever maximum length random password via a password management app, with two-factor authentication enabled in either case.
Except that every site has a different maximum number of characters, requires different special characters, some of them don't allow your favorite special characters, etc. So there's no way you can consistently use some complex patterns that you could actually possibly remember.
NIST's latest guidelines say passwords should be at least eight characters long
I tried "at least eight characters long" but it said passwords could not contain spaces.
NIST's SP 800-63 also says that passwords are supposed to be stored in a format resistant to offline cracking. NTLM never was particularly resistant and, like unix crypt was, should have been retired many years ago.
Moderating "-1, Disagree" is simple censorship. Have the guts to post your opinion.
If the password isn't protecting anything of value then 1 character will do - for example any site that makes you create an account so you can use it once.
If the attacker is rate limited and is only interested in one account then a 4 digit PIN will do - think bank cards
If the attacker can attack any one of 50,000 employees and is only rate limited per account a pass phrase of 4 words should be used.
If the attacker has the hash of the pass phrase then a pass phrase of 5 words should be used.
If the attacker has the hashes of 50,000+ phrases then a pass phrase of 6 words should be used.
8 random character passwords are useless, they too strong for the rate limited single account, impossible for 50,000 employees to remember and worthless against an attacker with the hash of the password.
You should also fire everyone involved in the 8 character, at least one upper, one lower, one number and one one special character and change your password every 3 months people. After 6 months almost every employee gives up on creating a strong password and uses a common 6 letter English word, capitalizes the first letter, puts in the number 1 and then a '!'. They then increment the number every 3 months.