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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Realistically, how much added security does having a passphrase on a ssh key have?

Let's assume ssh key brute force is unrealistic. It seems to me your greatest vulnerability would be someone gaining access to a client filesystem. If that's the case then key loggers and a host of ...
6
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3answers
857 views

Attack vectors for brute-forcing website passwords

When talking about password security, a lot of discussion centers on the risk of a password being guessed in a brute-force attack. For websites where a user has registered an account, what are the ...
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2answers
9k views

Is it possible to crack a PIN / PUK code on a phone SIM card?

When deploying a mobile phone best practices policy, one of the points which were raised was the requirement for the user to protect his SIM card with a PIN. The theory is that three failed attempts ...
6
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1answer
635 views

Harden a server against mass SSH DoS attacks

How can a Linux server be protected against an attacker that tries to open a large number of SSH sessions (probably trying to brute force a password) that no ports remain to be able to legitimately ...
6
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3answers
919 views

NTLMv2 resistance to bruteforcing

I have a question regarding NTLMv2 resistance to password bruteforcing. I know that some modern graphic processors (like Radeon 6990) are able to calculate billions hashes per second and crack NTLM ...
6
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2answers
665 views

How can I restrict users' connection attempts to my FTP server?

Is there any way possible to restrict user to make a connection to the FTP server on my Windows XP computer? I have an FTP server established in Windows XP and now I want to make access to that FTP ...
6
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1answer
7k views

What is the fail2ban default setting for SSH login attempts?

I tried to block myself from my own server to test if fail2ban works correctly, so I tried ssh login and used a wrong password over and over. But I was blocked only after 13 failed logins instead of ...
6
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1answer
12k views

Is my router vulnerable if WPS is enabled but WPS pin code is disabled?

I was reading about Reaver and wi-fi protected setups (WPS). In my Netgear router I have the option to disable the WPS pin code, but still have the WPS push button enabled. Am I secured with such ...
6
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1answer
174 views

Can/do botnets brute force “high value” users of services like Gmail?

On an intranet a login is generally disabled after a very small number of failed logins. But a public email service like Gmail can't do the same, otherwise pranksters would just be continuously ...
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3answers
285 views

How do I secure my advertisement space against ad overlay browser attachments?

I don't really have an issue with advertisements simply being blocked by individual users who are visiting a customers site or my own site. As an individual you have the freedom to choose not to look ...
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5answers
2k views

What password cracking software is commonly used?

I am curious to know how secure my passwords are. What password cracking software is commonly used? Preferably open source. EDIT: I am actually looking to crack my passwords used on services I ...
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5answers
1k views

Increased security with keepass

I am using keepass for securing passwords. I have a reasonable password, but if someone got hold of the file I am sure eventually they could brute force it. I was thinking of using a key file as ...
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4answers
176 views

software to keep a list of IP that try to access ssh over a set of rules and feasibility

i'm interested in software or set of scripts to keep a lists of filtered IP that attempt to brute-force ssh, and to label an IP as brute-forcing i would add some checks like: one attempt to log as ...
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4answers
4k views

Brute force vs other methods of recovering passwords from shadow file

Do you know any good approach for de-hashing/actually bruteforcing hashed passwords in the shadow file? On various operating systems, any good solutions/methods/programs. Or is it better to upload ...
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4answers
3k views

Finding all links under a website

How can i find all directories and links under a website? Note that there is no link from home page to all other pages. For example if i have a domain like this users.company.com and each user will ...
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3answers
2k views

What are the odds of brute-forcing an archive with 256-bit encryption?

I have a file (a stand-alone archive). I lost the password to it, but it has been encrypted using 256-bit encryption. The password is some 20-odd characters long (including non-alphanumeric ...
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3answers
63k views

Wordlists on Kali Linux?

I notice that in /usr/share/wordlists in Kali Linux (former Backtrack) there are some lists. Are they used to bruteforce something? Is there specific list for specific kind of attacks?
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2answers
1k views

Web & insecure HTTP - Using RSA for encrypting passwords on the client side

I used client side password hashing in my register and login project. Its purpose is to prevent passive adversaries/eavesdroppers from discovering users' plaintext passwords when HTTP requests are in ...
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6answers
6k views

How can I generate custom brute-force dictionaries?

I have found during testing that companies often use variations of their names for critical passwords (for example Microsoft's password might be M1cr0s0f+ or m1cros0ft etc etc). So if I gave it the ...
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2answers
866 views

Do SSD's offer significant performance boost for Scrypt?

Being a memory intensive hash, I was wondering if SSD's offer any appreciable performance boost for brute force attacks.
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1answer
156 views

Could a password hash that's prone to more collisions provide better overall security?

Website security breaches seem to be a common occurrence, giving the attacker password hashes that he can conduct a brute force attack against, often given him a list of passwords that will work on ...
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4answers
525 views

Hashing a key: less entropy than the key itself

A web API needs to store a 'key' for authentication, in much the same fashion as a password but at 128 characters. My concern is that the salted SHA1 hash for the key has less entropy than the key ...
5
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2answers
663 views

mysql security logging

Is there any logging available that logs mysql connection attempts to the port, login attempts, and times succeeded with username, IP address and date time? Im trying to detect brute force attempts. ...
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4answers
3k views

How can hackers guess passwords (using dictionary attack or brute force) without being locked out?

Nowadays almost every website you want to register in; is asking you to create a complicated password...But why cant we use simple passwords? I am just wondering because in case of multiple wrong ...
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1answer
744 views

Wordpress Brute Force Attacker knows real admin Username -

I've noticed a brute force attempt on several different Wordpress installs that know the right admin user name for those respective sites... It seems very strange that the hacker would be able to ...
5
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2answers
296 views

Are more passwords breached via dictionary/bf attacks or via packet-sniffers/key-loggers?

This question has always intrigued me whenever the subject of passwords is brought up. Does anyone have direct experience or a reputable source to answer what percentage of password breaches are ...
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1answer
1k views

Can a Bitlocker To Go user pin be brute forced?

I have a external hard disk and protected a partition on it with Bitlocker To Go. I printed the recovery code but I lost it. I can't remember the user PIN either. If I could only know the first ...
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2answers
480 views

Connection on port 3387 Event viewer says “authorized”

This event shows up multiple times within a minute like it was being brute-forced, but it says "authorized". My question is: Is there anyway I can see any commands that came in from this connection? I ...
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8answers
363 views

Does it take longer to brute force a password starting with z than one starting with a?

I was wondering about the following: If someone tries to get my password with Brute Force, will a password starting with "a" guessed faster than one starting with "z" ? In this case assume the ...
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3answers
2k views

Avoiding Brute Force Attacks in a Web Based Login Form

My login form uses Ajax so it doesn't need to reload if the password is wrong. A PHP script process the request and creates the session if the credentials are right. My idea is to have the PHP script ...
4
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4answers
640 views

Insecure to require numbers in passwords?

Earlier, I went to a site that required a number and special character, and it got me thinking – wouldn't that make the password easier to brute force? If you assume most passwords have around 12 ...
4
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3answers
190 views

What alternatives do email services provide when an account is hacked?

I am concerned about how does email services like Yahoo, Gmail, Hotmail etc provide security to their costumers and prevent their account from being compromised. For example, I have seen that if ...
4
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2answers
6k views

Can DES-based hashed password be recovered if salt is known?

Can a hashed password be recovered if the hashing is done with DES based crypt function in PHP and both the hash and salt are known by the attacker? Consider the following example: $salt = 'mysalt'; ...
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4answers
2k views

How unlikely is it that a Google Doc link is guessed?

Most (if not all) of us know that a Google Doc link looks something like this: https://docs.google.com/document/d/13P3p5bA3lslqEJT1BGeTL1L5ZrQq_fSov_56jT9vf0I/edit There are becoming several tools ...
4
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4answers
571 views

Can't brute force password cracking somehow be throttled?

Online articles mention the importance of a strong password and suggest that hacking tools allows bad guys to attempt millions of passwords per second. I am wondering why OSes and websites and such ...
4
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2answers
4k views

Faster methods for decrypting a TrueCrypt disk, esp. knowing the algorithms used

I encrypted (with TrueCrypt) all my hard drives and had the passwords stored in an encrypted file on my USB disk. The passwords are all (except one) 50 character randomly-generated ciphers, there's no ...
4
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2answers
659 views

How can i calculate the number of possible passwords?

I have found a flaw in a site where the password reset feature resets passwords in the following format UpperCaseLetter-Number-LowerCaseLetter-Number-LowerCaseLetter-Number-UpperCaseLetter ...
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1answer
1k views

Can this be a DoS Attack?

When I'm checking my log, I found like 15k events of " PAM service(sshd) ignoring max retries; 6 > 3 " I know this might be normal, and considered as Brute-Force attack, but can it be classified as ...
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4answers
2k views

Throttling failed login attempts: exponential timeout? by IP? using a session cookie? captcha?

I'm beginning to think this is not as simple as it looks, and many "accepted" answers here and in SO have alternative answers that criticize them. Here is what I have gathered so far Most of what I ...
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3answers
2k views

Securing AES 128 encrypted ZIPs against brute force attacks

How long would it take to brute force decrypt an AES 128 encrypted zip file if the password is 8 characters long in the range of A-Z, a-z, 1-9? Does it make any difference if .NET's System.Random ...
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4answers
1k views

Brute-force heuristics used in password cracking

Existing questions on this site discuss some of the heuristics used by password cracking tools to avoid doing a completely naive brute-force search (for example, "dictionary word with number ...
4
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3answers
237 views

Is there any reason in particular encryption keys aren't arbitrarily large?

It's my understanding that the more bits an encryption key has, the longer it takes to break the encryption. What is the down side of having a larger encryption key or why don't we see keys of size ...
4
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2answers
885 views

Known Password Lengths and security considerations

Many people wil often brag about the length of their password, like "yeah nobody is ever going to crack my password cause its 22 characters long." I was thinking, if you knew the exact length of their ...
4
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1answer
7k views

Is brute-forcing the only way to crack WPA?

I don't know much about how WPA algorithms work internally. Is brute-forcing an AP the only way to crack WPA? (or to get associated with AP) Another question is about Reaver-WPS, what if an access ...
4
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2answers
154 views

How can you I detect low frequency brute forcing over multiple connections?

While I realize that servers can easily detect brute forcing strategies via a single I.P, it seems that servers would be vulnerable to a distributed attack from a botnet, with each computer attempting ...
4
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2answers
8k views

Estimated cost to make a brute-force WPA2 attack feasible

It's been shown that a brute-force attack on WPA2-Personal is possible in a reasonable amount of time. These successful attacks appear to be limited, however, to researchers who have the budget to ...
4
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1answer
795 views

Securing a simple webservice against brute-force with mod-security

I want to provide basic defense against brute-force attacks against a simple HTTPS web service. The web service provides a login method (let's say at http://example.org/login) which gets passed a ...
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1answer
729 views

Reasonable (BruteForce) Attempts/Second Estimate?

I've read various articles on password strength and passwords vs pass phrases (including the one from XKCD and its thread here), but most of those articles seem to be focused on online passwords, and ...
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0answers
54 views

Random padding in hash functions

In this answer, it was recommended that you add random padding when hashing messages for a trusted timestamp, such as for predictions, in order to avoid dictionary and brute force attacks (at least ...
4
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1answer
389 views

WPA2 audit tool

For the purposes of my own research, I have a very modest budget to set up a modest WPA2 brute-forcer supported by GPU(s). I've done some homework: Brute-Force GPU Password Crackers How to setup ...