Questions tagged [password-cracking]

for questions relating to the cracking of passwords and the practices to mitigate against passwords being cracked.

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1answer
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John the ripper multiple mask attack

I am going to use John the Ripper on a multi-core server to crack about 400 Windows NT hashes. Depending on my CPU capacities I want to check all passwords that satisfy following masks: ?1?1?1?1?1?1?...
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2answers
4k views

Should I use rainbow tables or bruteforce (NTLM)?

As part of security testing, I will receive around 150 to 200 Active Directory password hashes from Windows Server 2012 R2 (using NTLM?). I have found NTLM rainbow tables (1,5 TB total), that covers ...
8
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2answers
234 views

I'm conducting a study involving passwords, and need a method that assigns a numerical value to the complexity of a password

I'm currently a student and am conducting a science fair project for my high school. The study involves collecting human-generated passwords and testing them for complexity, or "crack-ability," to ...
2
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1answer
188 views

How to safely extract hashes from domain controller for auditing?

I am looking for either tools or method that will extract the hashes and store them securely so that they can be placed onto a dedicated cracking station. Obviously, they need to be transmitted and ...
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1answer
475 views

Decrypting a text encrypted with aes128 cipher algorithm [closed]

I found this challenge from a CS academy site and I was intrigued: A message was encrypted using the following openSSL command. What is the password used to encrypt the message? What is the secret ...
2
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3answers
1k views

is the hash of a hash of a password, equally or more safe than hashing just once? [duplicate]

I am told that is quite easy to crack passwords when an attacker obtains a list of hashes of these passwords. This is quite easily compared to hashes of pre-computed common passwords, or brute-force ...
0
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1answer
1k views

Efficient Way to Brute Force With Large Wordlist

I am considering attempting to perform an SSH brute force attack on my own device in order to test its security, but I have run into an issue with the wordlist. I know my own password format, as well ...
0
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1answer
441 views

Using unencrypted parts of encrypted file to recover password (7zip)

I have forgotten the password for an encrypted 7zip file (the filenames are not hidden), and I have copies of some of the unencrypted files. Is there a way I can use this to find out what the password ...
9
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4answers
3k views

Password manager vs password book

I have seen a lot of discussion online surrounding whether using password management software is more secure than writing your passwords down on paper and vice versa. However, a lot of this discussion ...
1
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1answer
6k views

Cant crack Responder hashes with John or Hashcat

I ran Responder in a test network and obtained hashes from a Windows machine. The logs for the machine show something like this (some bytes changed for security reasons) and are stored in a file ...
2
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2answers
183 views

How safe is this scenario security wise

In a project I am working on, I needed to write some cron job scripts, which purpose is, to access some external API's, which have information that shouldn't be accessible by the public. The external ...
3
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3answers
9k views

Does aircrack-ng use GPU/CUDA capabilities?

As stated, does aircrack-ng when brute forcing a WPA2 handshake capture use GPU/CUDA resources such as a program like Hashcat does?
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1answer
42 views

Is there a way to customize the authentication mechanism on an Android Device?

Android comes with authentication mechanisms like the lockscreen pattern. Is there a way to customize those patterns (e.g. adding nodes, changing colors, modifying the ruleset)? Or can I even ...
1
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2answers
289 views

Check the “security” of a password [closed]

I'm trying to find a tool to validate the security of a password and I've come across cracklib or libcrack2 (on Debian), which seems to be used a lot for the task and appears to do exactly what I ...
0
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1answer
156 views

How to recover account with an old phone number?

Over the last few years many online portals, email and social networks have linked user accounts with mobile numbers that can be used for account recovery, this way was pretty cool and secure as well. ...
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1answer
5k views

reaver - [!] WARNING: Failed to associate with xx:xx:xx:xx:xx:xx (ESSID: (null))

I am familiar with dict-password cracking but I recently moved on to reaver. When I run reaver, it pops up with an error [!] WARNING: Failed to associate with xx:xx:xx:xx:xx:xx (ESSID: (null)). I ...
0
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1answer
3k views

John the Ripper Character Lists

How is it possible to use or prioritize umlauted characters - ä ö ü ß Ä Ö Ü - whilst brute forcing. I'm not using any wordlist, only dozens of CPU threads via the following command : ./john --fork=...
4
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2answers
2k views

Is it possible to dump an exe from ram and create a distributable exe from it?

Is it possible to dump the ram and get an exe and use that ram dump to distribute an app? If so, is this something that is a practical concern and if so how best should a developer protect against it? ...
0
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1answer
460 views

Why is the password hashes in my database the exact same for all my users? [closed]

The hash is 1a469f2c34699d2b4ac3343fe6020a, all of my users passwords have this password hash when i looked in the database. So if I would try to crack a users password how am I supposed to do that if ...
1
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2answers
174 views

Protecting Passwords Using Short Hash Length

Does anybody use deliberately short hash lengths for passwords to increase the chance of false positive collisions in the event of a brute force attack on the database? When trying to decide on a ...
0
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1answer
5k views

samdump2 Error reading ControlSet: _RegOpenKey

I copied both SAM and SYSTEM files from my Windows7 OS, and then used this command to read the content of the SAM file samdump2 SAM SYSTEM > mdp_chiffres.txt, but i'm getting this error Error ...
6
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5answers
1k views

If A Password Is Unique, Does It Really Matter How “Strong” It Is?

People seemed to find this "If a Password is Super-Strong Does it Matter if It's Unique" question very interesting, but it actually reminded me that the converse question is interesting, too: If you ...
1
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0answers
4k views

John the Ripper doesn't use my wordlist file properly

When I use JtR to crack an encrypted zip file I have, it seems like JtR doesn't go through the wordlist I have ... I do the following steps: $ brew install john-jumbo $ export PATH=$PATH:/usr/local/...
11
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4answers
5k views

What's the best length for randomly generated passwords? (Security vs. compatibility)

It's generally recommend to use a unique password for each online service, a random password generator to create them and a password manager to store them. I've started to replace all my online ...
3
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1answer
4k views

Find salt from md5 hash if password is known

I have a salted MD5 hash and I also know the password. How can I recover the salt using tools like John The Ripper (I have JTR jumbo installed)?
4
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2answers
3k views

How to extract the password hash from a password-protected container?

How can you extract the hash of the password from an encrypted container, such as a KeePass file, or a LUKS, TrueCrypt or Veracrypt volume? I tried to use keepass2john from John the Ripper, but it ...
2
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1answer
415 views

Are there bruteforce programs that use letters of other languages? Arabic? Greek?

I came across a site that had the password strength meter. I tried using 'password' and the meter did not like my password. Then I happened to try 'password' but I used the arabic translation for 'a' ...
0
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1answer
1k views

John the Ripper MaxLen

From the documentation MaxLen = LENGTH Maximum password length to try. The default is 8 (or CHARSET_LENGTH as defined in src/params.h at compile time). I've compiled it to support up to 62 ...
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2answers
86 views

How (un)safe is it to protect an admin page with a simple query-string password? [duplicate]

I have a very simple admin web page that simply displays feedback messages left by users of my mobile app. The messages are sent from the app to a web server, and to view the messages one needs to ...
4
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1answer
647 views

cracking krb5 passwords (des3-hmac-sha1 and des-cbc-crc ) [closed]

I'm trying to audit kerberos passwords. The available formats are des3-hmac-sha1 and des-cbc-crc but I cannot find a possibility/a tool to crack them. For other hash-types I used John the Ripper, but ...
-1
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1answer
670 views

How do I find out how long a password is for a 7zip aes 256 encryption? [closed]

I lost password to a 7zip, nothing important in it. But i'll still like to access it. I heard there is a way to find out how long the password is, but I dont know how.
3
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1answer
312 views

How to recover original excel password

I know how to remove the password protection from an excel document, but I was wondering if there was a method to recover the original password. I have a document encrypted with a 64 character ...
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1answer
109 views

Are there any sources on how common the most frequently used passwords are? [closed]

For example, I'm trying to work what percentage of passwords are within the top 500 most common passwords.
0
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3answers
297 views

how to protect from LM hash cracking

I have read that modifying the NoLMHash value in the registry can prevent LM hashing, but I still can dump the hash after doing this. What does this key do? How can I prevent LM password hash dumping ...
5
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2answers
2k views

How to brute-force a somewhat remembered aescrypt password?

I have a file I encrypted with AES via aescrypt about 5 years ago. I remember a lot of things about the password with several prefixes and suffixes. I have experience as a programmer but not with ...
4
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2answers
889 views

When hashing, do longer messages have a higher chance of collisions?

While discussing maximum password lengths, a poster made this comment: The longer the allowed input, the easier to supply an input that could cause a hash collision To explain (since the lack of ...
3
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3answers
187 views

Password Hashing Flaw

Disclaimer: I know about the dangers of rolling your own auth, this example is intended to be used in a demo for various hashing methods. I wrote this Node.js func to run server side to reinforce ...
1
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1answer
401 views

Passwords - extended dictionary vs dictionary attacks

Taking inspiration from Diceware and the other passphrase generators, I took a dictionary of 20k English words and used a script to generate typos of them, resulting in 7M "words", giving 22.7 bits of ...
5
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1answer
4k views

Attack WPA password with hashcat - Settings and resources for “german” passwords?

I'd like to prove to a friend of mine that his wifi is insecure and learn something about password cracking on the way. The guy I am talking about does not believe in strong passwords but in SSID ...
0
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1answer
200 views

Will I jeopardize security if I store the first three characters (hashed) in a separate table?

In order for a customer service representative to identify a customer, they'd like to ask the customer for the three first characters of her password. The minimum length of the password is currently ...
28
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2answers
4k views

Is it possible for my password to have more than one password combination?

Can my password have more than one password combination? I read up on physical combination locks (the lock you open with numbers) and I learned that a combination lock can have more than one ...
9
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1answer
13k views

Bruteforce with hashcat, how to set the mask properly?

Let's say I've an hash of this type: test::::4e45c7bab093d7011e9b3a5df7d9fa88212beac5ac9c8c47:d6ff3373aa353f3b:123456 I would like to bruteforce it using hashcat, but I'm failing to set the correct ...
3
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1answer
359 views

Customize John The Ripper BF technique

Is it possible for me to customize the way John the Ripper brute forces a .cap file? I, knowing my WiFi password, want to crack it fast as possible (no hit with word list). Can I customize John to ...
6
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1answer
5k views

How does PHP's password_hash() BCRYPT cost factor translate into cracking computation times

I am trying to fully understand the relationship between BCRYPT's COST factors and how much more time it would take a machine to crack a password with PHP 5.5's password_hash() The encryption times I ...
1
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1answer
162 views

Do I need high password security if I also require a Client Certificate for validation?

Due to an ongoing discussion in my office, I was wondering if anyone had any comments on whether password hashing security needs to be very strong if client certificate validation is also required for ...
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3answers
2k views

Is it useful to hash the password before sending to server for authentication? [duplicate]

In the design of a backend database, the password field suppose to be hashed using bcrypt. There are two approaches backend only: password = bcrypt(plain_passsword) frontend + backend = password = ...
0
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0answers
43 views

Should I use a Password manager or just use different passwords? [duplicate]

Reading this article on the BBC titled: Password guru regrets past advice It advises that people now use Password Managers: It recommended that organisations abandoned a policy of pushing their ...
1
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2answers
144 views

Securing data after laptop is lost or stolen

We have laptops encrypted and password protected. The scenario we're struggling is if user lose or report stolen laptop. Disabling workstation in AD and doing the rest standard procedures does not ...
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1answer
5k views

How To Crack The PDF Password? [duplicate]

I need to edit and merge some pdf files which are asking pasword. How can I crack the password?
0
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1answer
477 views

Is there a combination program that will generate a dictionary from a predefined list of words and numbers in specific order? [closed]

I'm sorry if this question has been asked, but I've already wasted 6 precious hours trying to find a program that will accomplish the task I'm requesting. (Perhaps I'm asking the wrong question?) ...

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