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Lessons from a Professional Password Cracker

themarkup.org

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Re: Lessons from a Professional Password Cracker

#2
The rockyou.com insight was new to me. I hadn't heard of this breach somehow. I was wondering how they had 32m users and read some more on Wikipedia and they had Facebook apps and some MySpace plugins.

From Wikipedia

> In December 2009, RockYou experienced a data breach resulting in the exposure of over 32 million user accounts. This resulted from storing user data in an unencrypted database (including user passwords in plain text instead of using a cryptographic hash) and not patching a ten-year-old SQL vulnerability. RockYou failed to provide a notification of the breach to users and miscommunicated the extent of the breach

Re: Lessons from a Professional Password Cracker

#3

The rockyou.com insight was new to me. I hadn't heard of this breach somehow. I was wondering how they had 32m users and read some more on Wikipedia and they had Facebook apps and some MySpace plugins. From Wikipedia > In December 2009, RockYou experienced a data breach resulting in the exposure of over 32 million user accounts. This resulted from storing user data in an unencrypted database (including user passwords…

Fun fact: rockyou.txt by now is probably one of the most common/famous wordlists out there, used for doing various types of dictionary attacks and the entire list ships by default with lots of tools, including Kali Linux which is a common distribution for pentesting.

Re: Lessons from a Professional Password Cracker

#5

I use this password for all my accounts: BingoBongo77. Is it secure? Edit: oh crap

Don't worry, all I can see is ••••••••••••. The browser builds in technology so that it conveniently shows you your password (BingoBingo77), but all I can see is ••••••••••••. Neat, right?

Re: Lessons from a Professional Password Cracker

#6

I use this password for all my accounts: BingoBongo77. Is it secure? Edit: oh crap

Don't worry, all I can see is ••••••••••••. The browser builds in technology so that it conveniently shows you your password (BingoBingo77), but all I can see is ••••••••••••. Neat, right?

Phew!

Re: Lessons from a Professional Password Cracker

#7
Some rules of thumb:

All Windows passwords shorter than about 10 characters shouldn't be considered secure, as the NT Hash at this point is so easily reversible that it's basically a "light obfuscation" at best. A single GPU can crack all 8-character passwords in minutes. The single best security setting on a Windows network is to increase the minimum password length to something like 14 characters. Use 20+ for privileged or service accounts.

The second best thing to do is to scan password hashes against "top password" lists and reject any that are in the top-N, where its up to your business policy what 'N' is. I recommend at least the top 10,000 most common passwords being outright rejected.

The third thing is to match against specific leaks. E.g.: if you have john.smith@foo.com and there is a leak of his email and password where the password matches your records, force a password change immediately.

All of the above assumes that MFA is in place, your servers are patched, and there are extensive audit logs on all authentication attempts.

Re: Lessons from a Professional Password Cracker

#8
meh. pro hackers do not crack or bruteforce passwords except as a last resort. they instead find some critical vulnerability that bypasses the need for passwords, or steal the browser sesion, or use malware. this is how so many people got crypto stolen despite strong passwords.

Re: Lessons from a Professional Password Cracker

#9

Some rules of thumb: All Windows passwords shorter than about 10 characters shouldn't be considered secure, as the NT Hash at this point is so easily reversible that it's basically a "light obfuscation" at best. A single GPU can crack all 8-character passwords in minutes. The single best security setting on a Windows network is to increase the minimum password length to something like 14 characters. Use 20+ for privi…

Is this still true now that LM hash v1 support has been dropped?
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