An attack using every possible input to attempt to produce the correct output. Typically the method of last resort when no weakness allows the use of a more restricted input set. E.g. trying all possible (or likely) passwords, in an attempt to guess the correct one.

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740 views

Is a password easier to brute force if it contains a repeating pattern?

My question is different from this previous question: Does repeating one word to form a password result in a similar pattern in its encrypted format?. I'm specifically wondering about brute force ...
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2answers
2k views

how long does it take to brute force varying encryption standards?

Let's say I want to encrypt information in a database. What would be the best encryption algorithm to use and why. I was thinking AES, since it's widely used as a government standard, but if the ...
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1answer
275 views

Is there any practical attack on port knocking method?

I was wondering, how can I bypass the port knocking method. Is there any public vulnerability or method for attacking port knocking services? For example: I know an SSH port is behind a port ...
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2answers
7k views

How long would it take to bruteforce an AES-128 protected pdf knowing the key is 20 letter long and that the charset is A-Z,0-9?

The question says everything, knowing that a pdf is protected using standard Adobe password encryption that comes with Acrobat Pro (which as far as i know is AES 128) how much would it take to ...
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1answer
2k views

Brute-force a passphrase, generated by `pwgen 16 -s`, of a GPG CAST5 archive

A sad story: One of our hard drives failed. While it was failing, we managed to take a quick backup. As it is our standard practice, we encrypted the backup using GPG (by however method Duplicity uses ...
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1answer
340 views

Why do so many cracking attempts originate from China?

I recently put a Linux server online and it didn't take long until I had the first attempts to brute-force the SSH login. It's not that I am worried about that - I trust the security of my server. But ...
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1answer
2k views

Cracking MD5 passwords with the same salt

How long would it take to crack passwords up to 10 letters long if you knew the hashes were MD5 with a salt (that you know)?
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1answer
1k views

Brute-Force GPU Password Crackers

Brute-force password cracker programs which claim GPU support include John the Ripper, ighashgpu, oclHashcat, and others. oclHashcat appears one of the more popular, but I am not sure which AMD/ATI ...
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1answer
718 views

Pointers for john the ripper rulesets

I've been pouring over the JtR ruleset documentation and making little progress. I understand how to use it to make various permutations from a given wordlist, that's fine. However, I'm trying to ...
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2answers
221 views

Cloud services - A window to outsourcing illegal activities?

Recently I was exposed to a number of stories where alleged illegal activities (for this case, we can take brute-force) are outsourced to the cloud, and are run by the cloud providers. The providers, ...
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1answer
802 views

Pen test cell-phones

A customer has asked to conduct a pen-test on the phones of employees. The target is text messages in the phones. Text messages are stored on the SIM for security reasons. Physical access to the ...
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4answers
482 views

One-Time-Passwords resist against bruteforce attacks? Immune Alternative?

Does a One-Time-Password like Google Authenticator or YubiKey protect against brute force attacks with unlimited computer power? If not, what algorithems are immune to bruteforce attacks against ...
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2answers
114 views

Are repeating random patterns weaker than non repeating random patterns?

Which would be harder to crack: a password comprising of n characters randomly selected or a password comprising of x randomly selected characters repeated m times so that m*x=n. For example: ...
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1answer
1k views

Hydra bruteforce and JSON

I am having problems with Hydra and a JSON payload. The login request (intercepted with Fiddler), is the following: POST http://architectureservice.test.com/api/v1/login HTTP/1.1 Host: ...
2
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1answer
147 views

Username Enumeration as a Threat

I have found a Username Enumeration Vulnerability through which I am able to determine whether a particular user is registered with that site. While trying to brute force, after 5 attempts it asks for ...
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1answer
164 views

Given a hash, salt, charset and password length, how do you get the password without brute-forcing it?

I got that question on an exercise and I'm not sure what to answer. Without conventional brute-forcing and without a rainbow table, how could I find out the password? An improved brute-force ...
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1answer
807 views

How large RSA-keys could the worlds combined computer power factorize in reasonable time?

If you combined every microprocessor on earth into one humongous computational cluster, how large RSA-keys could you factor in reasonable time (lets say a few years)? I know from reading the answers ...
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2answers
856 views

Can you crack a Mailinator “Alternate Inbox Name?”

From their FAQ: What are "Alternate Inbox Names" ? There are 2 ways to get email into any given inbox. When you check an inbox, listed at the top is the Alternate Inbox name. Emailing that alternate ...
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2answers
205 views

ASLR in Ubuntu 11.10

In many of the exploits I see nowadays, brute forcing is a common method of bypassing ASLR on 32 bit machines. However, many of these exploits crash the current process, for example, PHP. Isn't the ...
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1answer
7k views

How to use http-get-form in THC-Hydra?

I've been messing with Hydra (Brute Force) to solve the "Damn Vulnerable Web App" brute force section but the problem is when I use http-get-form it said: Warning: child 1 seems to have died, ...
2
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1answer
48 views

Avoid brute-force enumeration of customers in a SaaS application

I'm involved in the development of a SaaS application. We host the application for different customers. A customer is a company. Each customer gets access to their hosted instance of the application ...
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2answers
284 views

Temporarily save failed logins password hashes for using against brute force attack

My question is about online brute force attacks, that try to authenticate in the website. 1) For the first case if the requests are coming from the same ip, I think this are relatively easy as after ...
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0answers
60 views

Why does Hydra not stop when it finds a password? [closed]

Why does Hydra 8.1 not stop when it finds a password? I am using the -P option with a file that has over 5 Million passwords in it and the correct SSH password is located at approx. line 2100, but ...
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4answers
16k views

Brute-force an SSH-login that has only a 4-letter password

Suppose, you know that a certain computer is only protected by such a short password, then you could just try every possible combination easily. How would a script look like, that tries to crack that ...
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1answer
409 views

Use brute force to mitigate brute force

Just an idea I had, and I am sure there is a lot of material about this subject, so I am looking for a pointer as to where I can find more information. My idea is this... When storing a password in ...
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2answers
545 views

Known password length, brute force character in place?

We all know that brute forcing is a very slow process and trying all unnecessary possibilities is dumb. By knowing the password length, we can skip trying possibilities of other password lengths and ...
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5answers
320 views

Is there something similar to DNSBL's for protecting against forceful browsing?

I want to protect a couple of Apache webservers against forceful browsing. Lately there have been multiple scans querying for non-existent applications on them like phpMyAdmin, notably known for their ...
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2answers
157 views

do ISPs implement security measures?

For example, if a user is receiving a denial of service attack, with huge amounts of packets being sent to him to disrupt his service, will the ISP notice and stop the offending traffic? Another ...
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2answers
382 views

Seeking advice on how to build a box to brute force hashes? [closed]

I work in a startup security firm, and I need to build a GPU-based to brute force password/hashes, which can be used to validate password strength and test hashing algorithms. I expect some high ...
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3answers
2k views

What utilities exist to brute force a username and password?

I'm trying to persuade management to purchase two factor authentication for securing VPN and terminal server access. I've made significant progress by demoing TSGrinder, but would like to list other ...
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2answers
2k views

Brute force alphanumeric password using JohnTheRipper

I recently recovered a zip archive with some files I need access to, but I can't remember the password. All I can remember is that the password was short (around 3-4 characters), and contained only ...
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2answers
283 views

In what situations can a hacker try to break passwords millions of times? [duplicate]

I keep reading about situations where a hacker could "easily" brute force a password (most recent example) but I'm confused about when some has an opportunity to do this kind of thing. If it is a ...
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1answer
822 views

How bruteforce works code wise

I was wondering how bruteforce methods work from a code level. How does the code get access to a login page for example and insert information into the necessary fields? And is the code able to ...
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4answers
904 views

Our logs showing a lot of SSH brute force attacks originating on Port 11

this forum has been brilliant so far. Just wondering if I can get a bit more help: Can I get some info on a large amount of SSH brute force attacks originating from port 11 on the external host over ...
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2answers
175 views

Session Hijacking through sessionId brute-forcing possible?

cookies usually contain a sessionId to keep track of a logged user. What would prevent a malicious user to forge millions of requests with random sessionIds and send them to a server, hoping to ...
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3answers
445 views

Brute Force In Order Or Random?

Which is faster, on average to find the original plain text of a hash: brute force in-order, or with random plaintexts?
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2answers
973 views

Password Protected Zip: if attacker had one file, can use it to decrypt all files?

Consider a folder containing the following files: (file1.txt, file2.doc, file3.pdf) all zipped and password protected, if attacker had one of these file, can use it for decrypting all without knowing ...
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2answers
608 views

Brute force a GUI login?

I know I have read somewhere that the reason the UAC prompt in Windows 7 was employed is that viruses that would supposedly execute privileged instructions won't be able to "click" the confirm button ...
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1answer
194 views

Stripping / appending characters from user password before hashing to conceal it forever?

I had this idea to permanently conceal user password by requiring minimum length then stripping certain characters. For example if the user password is secret123, the system will strip it down to ...
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3answers
222 views

Touch tone phone username and password

I just got off the phone with Fidelity, who manage the health benefits for the company where I work. Before talking to a person, I was prompted to enter my username and password on the numeric keypad: ...
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2answers
276 views

How do you know if blowfish key is correct?

Encryption novice here so maybe this question makes no sense... Obviously if you know what the clear text is and it decrypts right, you have it. But if someone is running through keys to break the ...
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1answer
157 views

Botnet Attempting to Login to Website

Our server has recently become a target of what appears to be a botnet attack. The first indication was an insane amount of traffic to one of our client's websites - so heavy that the server entirely ...
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1answer
1k views

How many possibilities can today's computers check (per second) in a SHA512 hash of a 50-byte-long random entry? [closed]

The problem I want to avoid is "brute force" attacks against a database. So if I add a 50-byte-long cryptographically random salt to my information (which I don't need to retrieve, just its hash) - is ...
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3answers
297 views

Mass account lockout prevention using CSRF tokens

I'm currently working on reducing the risk of mass account lockout on a site that (unfortunately) issues sequential, numeric user IDs. Changing the structure of the userID is not an option at this ...
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3answers
58 views

How can hackers access WordPress usernames? [duplicate]

Recently I've had brute force attack attempts on some of my WordPress sites and the attackers are using actual usernames other than the default admin (which was removed). How is it possible for them ...
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4answers
475 views

Is there any defense against Brute-Force done on a local encrypted file?

Let me start off by saying I don't know very much about encryption, hashing, cracking, etc. I'm just a typical computer enthusiasts, programmer and researcher with many questions. So, I've discovered ...
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1answer
11k views

Forgot password to 7-Zip archive

I think I already know the answer to this question, but I thought I'd ask the experts anyway. A few months back, I created a password-protected 7-Zip archive which housed the source code of a simple ...
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2answers
2k views

Computing RSA 1024-bit Decryption Performance [closed]

I want to be able to tell how many keys per second, using RSA 1024-bit keys, can be checked on a standard Pentium 4 system. How can I use this to determine decryption performance, and possibly ...
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2answers
488 views

Hash, encryption of file… key? Need help [closed]

So my previous question was with some help on pcap files as I am doing a security course and we have a challenge to figure out what was going on in our network. Now one of the files I retrieved is an ...
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2answers
31 views

Public/private key auth and VPN

If a server uses public/private key authentication to access SSH, will there be any advantage of restricting the access of SSH over VPN? This link describes both approaches to solve brute force ...