Let's say that a man decides to crack the password of a single account. He downloads some Brute force program and sets it to try every single password combination with different IPs. The same IP would be used until the captcha comes up, then it will be replaced by a new one, so facebook would not be able to stop the attack by blocking the IP.
facebook hacker brute force
So what does facebook do to prevent this? Because I don't see anything it can do besides lock the account, which is not practical. It may take months or years but with this method the hacker will eventually be able to log in, would he not?
Spoofing the IP address won't work either, because IP spoofing isn't easy to do when you want to not just sent packets but also receive the responses. When you want to brute-force a HTTP login, you will need to perform a TCP handshake first, which requires to be able to receive responses. Also you certainly want to parse the response to know if you were successful.
And even when you could theoretically use all 4 Billion IPv4 addresses the internet has to offer, multiplying your tries with 4 billion only gives you enough tries to bruteforce passwords with 4-6 additional characters (depending on how many different characters the password contains).
And last but not least, the main problem with brute-forcing via network is the bandwidth you have available which greatly limits your attempts per seconds compared with what you can do when you brute-force hashes locally.
Facebook has a built in method of determining a users chosen devices that are allowed to access the account. If someone from a new device attempts to log into my account I will receive a message (email or text) that a new device has attempted (or successfully) accessed my account. This in itself does not actually "stop" brute force attacks, but combined with two step authentication it can.
Facebook does temporarily lock accounts. After too many authentication failures, it temporarily locks the facebook account for a few hours, and requires a security question/verification code to unlock the account for more verification attempts. After a 24 timeout period, you can log in again. To the consumer, 24 hours without Facebook is not the end of the world. To the brute forcer, a 24 hr delay every X attempts is a major pain. It's a good compromise between usability and protection.
A brute force attack when an attacker uses a set of predefined values to attack a target and analyze the response until he succeeds. Success depends on the set of predefined values. If it is larger, it will take more time, but there is a better probability of success.
The most common and easiest to understand example of the brute force attack is the dictionary attack to crack passwords. In this, the attacker uses a password dictionary that contains millions of words that can be used as a password. The attacker tries these passwords one by one for authentication. If this dictionary contains the correct password, the attacker will succeed.
In a traditional brute force attack, the attacker just tries the combination of letters and numbers to generate a password sequentially. However, this traditional technique will take longer when the password is long enough. These attacks can take several minutes to several hours or several years, depending on the system used and length of password.
To prevent password cracking from brute force attacks, one should always use long and complex passwords. This makes it hard for attackers to guess the password, and brute force attacks will take too much time. Account lockout is another way to prevent the attacker from performing brute force attacks on web applications. However, for offline software, things are not as easy to secure.
A reverse brute force attack is another term that is associated with password cracking. It takes a reverse approach in password cracking. In this, the attacker tries one password against multiple usernames. Imagine if you know a password but do not have any idea of the usernames. In this case, you can try the same password and guess the different usernames until you find the working combination.
Now, you know that a brute-forcing attack is mainly used for password cracking. You can use it in any software, any website or any protocol which does not block requests after a few invalid trials. In this post, I am going to add a few brute force password-cracking tools for different protocols.
I am sure you already know about the Aircrack-ng tool. This is a popular brute force wifi password cracking tool available for free. I also mentioned this tool in our older post on most popular password-cracking tools. This tool comes with WEP/WPA/WPA2-PSK cracker and analysis tools to perform attacks on Wi-Fi 802.11. Aircrack-ng can be used for any NIC which supports raw monitoring mode.
It is available for Windows and Linux platforms. It has also been ported to run on iOS and Android platforms. You can try it on given platforms to see how this tool can be used for brute force wifi password cracking.
John the Ripper is another awesome tool that does not need any introduction. It has been a favorite choice for performing brute force attacks for a long time. This free password-cracking software was initially developed for Unix systems. Later, developers released it for various other platforms. Now, it supports fifteen different platforms including Unix, Windows, DOS, BeOS and OpenVMS.
L0phtCrack is known for its ability to crack Windows passwords. It uses dictionary attacks, brute force attacks, hybrid attacks and rainbow tables. The most notable features of L0phtcrack are scheduling, hash extraction from 64-bit Windows versions, multiprocessor algorithms and network monitoring and decoding. If you want to crack the password of a Windows system, you can try this tool.
Hashcat claims to be the fastest CPU-based password cracking tool. It is free and comes for Linux, Windows and Mac OS platforms. Hashcat supports various hashing algorithms including LM Hashes, MD4, MD5, SHA-family, Unix Crypt formats, MySQL and Cisco PIX. It supports various attacks including brute force attacks, combinator attacks, dictionary attacks, fingerprint attacks, hybrid attacks, mask attacks, permutation attack, rule-based attacks, table-lookup attacks and toggle-case attacks.
THC Hydra is known for its ability to crack passwords of network authentications by performing brute force attacks. It performs dictionary attacks against more than 30 protocols including Telnet, FTP, HTTP, HTTPS, SMB and more. It is available for various platforms including Linux, Windows/Cygwin, Solaris 11, FreeBSD 8.1, OpenBSD, OSX and QNX/Blackberry.
These are a few popular brute-forcing tools for password cracking. There are various other tools are also available which perform brute force on different kinds of authentication. If I just give an example of a few small tools, you will see most of the PDF-cracking and ZIP-cracking tools use the same brute force methods to perform attacks and crack passwords. There are many such tools available for free or paid.
The best way to prevent brute force attacks is to limit invalid logins. In this way, attacks can only hit and try passwords only for limited times. This is why web-based services start showing captchas if you hit the wrong passwords three times or they will block your IP address.
We can then use the -C flag to tell Hydra to run these specific combinations instead of looping through all the users and passwords. This drastically reduces the time taken to complete a brute-force attack.
We can also enforce password policies to change passwords every few weeks. Unfortunately, many individuals and businesses use the same passwords for years. This makes them easy targets for brute-force attacks.
Another way to prevent network-based brute-forcing is to limit authorization attempts. Brute-force attacks do not work if we lock accounts after a few failed login attempts. This is common in apps like Google and Facebook that lock your account if you fail a few login attempts.
Facebook then sends a 6 digit code on the user's phone number/email address which user has to enter in order to set a new password. To prevent brute force attacks (where a computer keeps trying every logical combination of numbers on the login page till eventually reaching the correct password), Facebook has limited 10-12 attempts per account before waiting. Exploiting this, Anand gained access to any account on Facebook.
Brute force protection was valid only on the main homepage, facebook.com. However a alternate URL, beta.facebook.com and mbasic.beta.facebook.com did not have the same protection. Exploiting this, he brute forced his way to gain access to any account at all by resetting their password. The newly set password could be used to login any account.
Belgian bug bounty hunter Arne Swinnen discovered that malicious actors could launch brute force attacks against Instagram accounts via the official Android application and via the registration page on instagram.com.
The first vulnerability, which Swinnen reported to Facebook in late December, could have been exploited to conduct brute force attacks against the authentication domain used by the Instagram app for Android.
Furthermore, the test showed that an attacker could have logged in to the compromised account from the same IP address that was used to brute-force the password, which indicated that security controls designed to protect accounts against unauthorized logins had not been in place.
Mänôz's findings revealed that hackers could have used the bug to sneak past authentication protections using brute force attacks (via TechCrunch). The hack isn't rocket science: bad actors who know the phone number you use for authentication could use it to link it to their own account, removing it from your Facebook account.
While would-be hackers are unlikely to have access to a six-digit authentication code sent to your phone number, the bug could have allowed them to guess that code multiple times until they got it right. According to the researcher, this is due to Meta failing to set an upper limit for the number of attempts that users can make when entering the one-time code. Worse, brute-force methods could have resulted in your account's 2FA protection being completely disabled. 2ff7e9595c
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