Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.

Hot answers tagged

95

The password hashes for MS Office 97-2003 are vulnerable to collision attacks. That is, multiple passwords exist that should be able to open the document. That also means that the password "iemuzqau" is not necessarily the original password that was set by the author. It is just one of the passwords that should be accepted, because it matches the internal ...


12

You must install some stuff. The same happened to me. But you can work with new hashcat 3.x and CPU in your vm, no problem on that: apt-get install libhwloc-dev ocl-icd-dev ocl-icd-opencl-dev And apt-get install pocl-opencl-icd This worked for me. I found it here. What I suggested It's a little different because you can install pocl with apt-get instead ...


8

You've got the right idea - this is a great way to learn. For beginning and intermediate cracking, the best general password lists are actual lists of passwords - those found in leaks with large general user bases. And the best general practice hash lists are the hashes from public leaks. Your best "bang for the buck", in my opinion, is the hashes.org "...


7

This is a good starting point to learn how the Mask Attack from oclHashcat works: https://hashcat.net/wiki/doku.php?id=mask_attack You need to add the commandline-parameter -a 3 so hashcat knows your going to use a mask attack. Hashcat comes with some predefined mask's (you can define your own also): ?l = abcdefghijklmnopqrstuvwxyz ?u = ...


6

Complexity rules like these cannot be natively captured by a single mask. Instead, a list of many masks that fit the criteria must be generated using other tools, such as the policygen tool from the PACK toolkit. $ policygen --minlength=8 --maxlength=20 \ --mindigit=1 --minlower=1 --minupper=1 --maxspecial=0 -o test1.masks $ policygen --minlength=8 --...


6

As stated by @RoyceWilliams, it does not seem to use CUDA. For this purpose, you might want to look at Pyrit, since it leverages CPUs and GPUs on the cracking process. NB: I wanted to leave this as a comment but I still don't have enough reputation.


6

Let me break down, what you want and what the equivalent hashcat options are. Hash-Type You want to crack a OSX v10.8+ hash, which according to the hashcat example hashes page (https://hashcat.net/wiki/doku.php?id=example_hashes) is type "7100", so: -m 7100. Specifying the correct hash type should also get rid of the "incorrect length" error. Attack-...


5

(This thread is cross-posted on the hashcat forums here. My answer there was too simplistic, so I'll try to do a better job here.) The basics For wordlists and rules, it sounds like you've already got the basics down. As long as the wordlists are in UTF-8, and the input method used to set the password is also UTF-8, then they should work well. I would ...


5

First, some answers to your meta-questions: hashcat does indeed understand the 7-character split and optimizes accordingly. hashcat also knows that LM is case-insensitive, so you can drop the custom character set without changing the speed of the attack. I'm not sure where you got the idea that hashcat's ?s character set does not include '#'. it ...


5

I assume you are talking about the Mask Attack and not Brute-force Attack which is outdated and replaced by Mask Attack. I had to add --pwd-min=8 to the list of parameters to force it to start at 8 digits from the get-go. Source: http://hashcat.net/forum/thread-1538.html


5

Your hashcat appears to be working correctly. 30 seconds is about how long it takes mine to run through every password in rockyou.txt It looks like the password is not in rockyou.txt which only contains a few hundred thousand passwords. I suggest you use some rules to make it guess some variations on the passwords in rockyou and/or find a larger ...


5

[Disclosure: I work for AgileBits, the makers of 1Password.] To give credit where credit is due (comics rarely have citation footnotes), this scheme is called "Diceware" and should be credited to Arnold Reinhold, who described it in 1995. What is absolutely crucial to the scheme is that words must be chosen from the list by a uniform random process. (...


5

I don't think so. There's only one mention of OpenCL or CUDA in the source code, and it appears to be a leftover from code copied from John the Ripper. Edited to answer your implicit question: if you want efficient WPA2 cracking on GPU, consider hashcat for the cracking, and hcxtools for conversion to the required format (hccapx). hashcat is superior to ...


5

Sounds like you're looking for --increment-min. This will start a bruteforce/mask attack at a minimum length. For example, this will try digits-only candidates, starting with length 7: hashcat -a 3 -m [hashtype] -i --increment-min=7 targethashes.list ?d?d?d?d?d?d?d?d?d?d You didn't directly ask this, but the deeper intent of your question appears to be "...


4

As of the current version (3.30), hashcat does not currently support truncated hashes beyond the half-MD5 modes. In my discussions with the team, I made the pitch (basically what I wrote here). So far, they have expressed non-interest in expanding partial-hash matching to other types, as it's considered to be out of scope for the project. But this could ...


4

Randomness is mindless. When an attacker tries to "guess" a password, he is actually trying to enter the mind of the human user and find out what that meatbag could have come up with. For instance, the attacker may say to himself "Mmh, this guy thinks he is smart, he may have made the first letter uppercase, and added a dot at the end. After all, he himself ...


4

You should read the wiki entry on Mask Attack. In particular, you want custom charsets and the examples. First, you define up to four custom character sets, -1 through -4. Then, you put your mask together. For each character position, you can use a fixed character (19, in the first example, is a literal) a standard charset, like ?a or ?l a custom ...


4

The syntax is hash:message Note that the length of the message is limited to 51 bytes. See hashcat example wiki page for details: https://hashcat.net/wiki/doku.php?id=example_hashes


4

Mask attack seems to be a good solution. Generate a .hcmask file with the following lines: $%-",Barbara?1walks?1the?1dog $%-",Barbara?1walks?1the?1?1dog ... And so on, where each line is has differences places for the special characters (?1). Since you know the phrase, and because the set of characters is small, the total number of lines should be very ...


4

No, it is not possible to crack just any SHA-1 hash. Currently, there are two main issues with using the hash function for security purposes (not specifically password hashing): It is a very fast hash, meaning a brute force attack will run much more quickly than it would if you were to correctly use a slow KDF. The fact that SHA-1 is fast does not allow you ...


4

JWT Token Structure As detailed on the JWT website (https://jwt.io/introduction/), JWT token consists of three parts separated by a dot (.), which are - Header, Payload and Signature. Both Header and Payload are Base64 encoded strings. Therefore a JWT token would typically look like this: Base64(Header).Base64(Payload).Signature The signature is ...


3

Hashcat supports rules for modifying word lists on the fly. You can prepend the username and append the salt in a rule file (save as something.rule): ^username $salt and use -r in Hashcat to call the rule file.


3

Generally yes, if you have enough time. If you know how long or in what format the salt is, it would help you. But the method is brute-force, as the any other hash-reversal: oclHashcat -m=0 b4fbb742bc2a24bc033dbfb4f4582e08 -a=3 userpassword?1?2?2?2?2?2?2 I didn't test that, but documentation is certainly good place to start.


3

Check the mask_attack page of the hashcat wiki. For your case: oclHashCat64.bin -m 2500 -a 3 -1 ?l?u?d ?1?1?1?1?1?1?1?1 [YOUR HASH OR HASH FILE] "-m 2500" specifies the WPA/WPA2 hash type, per hashcat documentation "-a 3" is the brute force attack mode "-1 ?l?u?d" says to use the character set of lowercase, uppercase, and digits (the character set you ...


3

Yes. The Dev.#* they list is Hashcat's way of showing the combined cracking speed of all GPU devices. Normally the Hashcat benchmark output would look like this: Hashtype: sha512crypt, SHA512(Unix) Speed.Dev.#1.: 147.5 kH/s (103.12ms) Speed.Dev.#2.: 138.1 kH/s (102.84ms) Speed.Dev.#3.: 148.0 kH/s (102.83ms) Speed.Dev.#4.: 148.3 kH/s (102.57ms) ...


3

Edit: I saw that you found your answer, but I'll add it here for completeness sake. (And I already had this written down). Hashcat doesn't guess the # of rounds, and the amount of rounds specified in your /etc/login.defs isn't properly applied. I took an example from my Linux box: $6$elIIOT8d$lXVE7ZxTaBnvyi3kgrVGOpq.I/tQU9CN....


3

The file format is MAC:message, as @atom already mentioned. By "MAC" I mean the value the HMAC produces, a.k.a. the hash, so the MAC comes first and then the message that this MAC is signing. In this setup, the goal is to crack the key that the message was signed with. (It seems that you can also try to crack the other value with -m 1460, but I haven't ...


3

Sounds like a combinator attack would be a good place to start. It takes two input wordlists and tries all combinations of the two. In your case, the "left" list would be the beginning of your known password and the "right" list would be the unknown portions. However, Hashcat only allows two input files to a combinator attack, but you can use the ...


3

Hashcat lets you load a list of masks from a file - one mask per line. [Edited to expand my previous too-brief answer above]: Hashcat also lets you specify up to 4 custom character sets using the -1, -2, -3, and -4 parameters. Your specific custom character set (upper, lower, underscore) could be specified like so (I'm using "2" to make it obvious that it'...


3

For any halfway decent hash function, even hashes that are completely unsuitable for cryptography, if you look for collisions by brute force, it doesn't matter how you explore the search space. Keeping a fixed prefix and changing the suffix, or keeping a fixed suffix and changing the prefix, are as good as any other method. That's because all hash functions ...


Only top voted, non community-wiki answers of a minimum length are eligible