Brute force attack is a type of hacker attack to obtain password. In this attack, the attacker tries as many possible combinations of a password as possible to arrive at the correct password.
The longer the password and the more complex the combination of characters, the longer the brute force attack takes and the harder the hacker’s job.
For this reason, it is always suggested to internet users, especially large organizations, to use complex passwords. Continue reading to see what types of brute force attacks are there and how to protect against them and examples of brute force attacks from the past years.
Key point of Brute force attack:
- In a brute force attack, the software tests all possible combinations of allowed characters to reach the password.
- The longer and more complex password is used, the more computing resources and time required for this attack.
- Credential filling attack, reverse brute force attack and dictionary attack are different methods of this attack that we explain about.
- Limiting failed logins, hashing, captcha implementation and two-step verification are some of the brute force countermeasures.
In this article we will cover:
- What is a Brute Force Attack?
- Different types of Brute Force attacks
- Examples of brute force attacks in the past years
- What are the best ways to protect against brute force attacks?
- Increasing cyber security using brute force attack tools
- Brute force attack in the world of cryptography
- Frequently asked questions on brute force attack
What is a Brute Force Attack?
Brute force attack is a trial and error method for decrypting login information and unlocking encrypted keys, in other words, unauthorized access to systems.
Brute force attacks use brute force instead of rational strategies. Just as a criminal might succeed in cracking a safe by trying several possible combinations, in brute force attacks software programs attempt to try all possible combinations of allowed characters in a sequence.
Cybercriminals usually use brute force attacks to gain access to websites, accounts, and networks. In the process of this attack, there is a possibility of installing malware, shutting down web applications or infiltrating data.
- A simple brute force attack usually uses automated tools to guess all possible passwords until finally arriving at the correct one. This is an old but effective attack method for cracking common passwords.
- The duration of brute force attacks varies. Weak passwords may take seconds to crack, and strong passwords may take hours or days.
- Organizations can use complex code combinations to prolong the attack time and buy more time to neutralize cyber attacks.
Different types of Brute Force attacks
There are different types of brute force attacks, some of which are mentioned below:
- Credential Stuffing Attack: Credential Stuffing attack happens after a user account is compromised and the attacker tries the compromised users’ password combinations on multiple systems.
- Reverse Brute Force Attack: In a Reverse Brute Force attack, the attacker uses a common password or a password he thinks is correct in multiple usernames or encrypted files to gain access to the network and data. Then the hacker tries to find the correct username by following the same normal brute force algorithm.
- Dictionary Attack: A dictionary attack is another type of brute force attack that uses all the words in a dictionary to find a password. An attacker can find longer passwords by adding numbers and characters to words.
Other types of brute force attacks may try common passwords such as “Password” “1234567” or other common numeric sequences or even sequences that match qwerty keyboard layouts before trying possible passwords.
Examples of brute force attacks in the past years
- 2009: Attackers used automated password-cracking scripts to target Yahoo accounts in an authentication program based on Yahoo Web Services, which they believed belonged to third-party ISPs and web applications.
- 2015: Hackers were able to penetrate 20,000 user accounts by performing millions of automated brute force attacks to gain access to Dunkin’s mobile app and Dunkin’ Donuts rewards.
- 2017: Cyber security criminals used brute force attacks to gain access to the internal networks of the British and Scottish parliaments.
- 2018: In this year, it became clear that the main password of the Firefox browser is exposed to brute force attacks due to a bug in the SHA 1 function. No one noticed this bug for almost 9 years.
- 2021: The National Security Agency warned of brute force attacks directed by a unit of the Russian Foreign Intelligence Service through a Kubernetes cluster.
- 2021: Hackers gained access to T-Mobile’s test environment. Then, using brute force attacks and other tools, they hacked IT servers, including servers containing customer data.
What are the best ways to protect against brute force attacks?
Organizations can strengthen their cybersecurity against brute force attacks by applying a combination of strategies. Some of these solutions are:
- Make the password more difficult: Making the password more complex increases the time it takes to crack the password. For this purpose, you can apply password management rules such as minimum password length and mandatory use of certain characters.
- Limit failed logins: Another way to protect systems and networks is to implement rules that block user access after multiple failed login attempts.
- Encryption and Hashing: Using 256-bit encryption and password hashing exponentially increases the time and computing power required to execute a brute force attack. In password hashing, a string of characters is stored in a separate database and hashed in such a way that similar password combinations have different hash values.
- CAPTCHA implementation: Captchas keep systems, networks, and websites accessible to human users while being a barrier to brute force attack tools like John the Ripper.
- Implement two-factor authentication (2FA): 2FA strategy is a type of multi-factor authentication that creates an additional layer of security for logging in by implementing two forms of authentication. For example, Apple users must enter their Apple ID along with a six-digit number displayed on one of their previous devices to log in to a new device.
The best strategy for greater security against brute force attacks is to use all or a combination of the above strategies.
Increasing cyber security using brute force attack tools
Brute force attack tools are sometimes used to test network security. Some common brute force attack tools are:
- Aircrack-ng tool: Aircrack is a collection of software for testing Windows, iOS, Linux and Android operating systems. Aircrack software uses a set of commonly used passwords to attack wireless networks.
- Hashcat: The Hashcat program can be used to test the strength of Windows, Linux and IOS against brute force attacks and Rule Based Attacks.
- L0phtCrack software: L0phtCrack software is used to test the vulnerability of the Windows operating system against the Rainbow Table Attack. From the summer of 2021 (1400), the new owners of this software are reviewing and presenting its open source version.
- John the Ripper: John the Ripper is a free and open source software for performing brute force and dictionary attacks. Organizations usually use this software to identify weak passwords and improve network security.
Brute force attack in the world of cryptography
As mentioned, brute force attacks include the use of sophisticated software to guess possible passwords and find the correct password and finally break into a system.
Theoretically, this type of attack can be used to identify the password or key of encrypted data. The time required for a successful brute force attack is a measure of the strength of an encrypted system. Of course, a brute force attack on a system that has fully complied with security measures requires more computing resources.
The longer the password, the more time it takes to guess the password. For this reason, the bit sizes of encryption keys have increased over time from the initial standard of 56 bits to 128 and then 256 bits.
Of course, cracking a 256-bit encryption key requires a high level of computing power that can only be attacked by supercomputers.
Since the use of supercomputers requires fully controlled environmental conditions and high energy efficiency, it can be concluded that advanced brute force attacks are generally directed by government actors.
However, password cracking is possible using modern GPUs and dedicated hardware called ASIC (ASIC), which are available to almost everyone.
Some forms of encryption, including One-Time Pad Cryptography, are impenetrable. Access to systems that use this type of encryption is usually done by exploiting human error in the system instead of a brute force attack.
Frequently asked questions on brute force attack
What is a Brute Force Attack?
Brute force attack is one of the old methods of hackers to obtain passwords of systems and accounts. In this attack, they test as many possible passwords as possible to find the password.
What are the ways to counter a brute force attack?
The main and most important method is to use a long and complex password. The longer and more complex the password, the more computing resources and time it takes to find it.
Brute force attack is one of the old methods of cybercriminals to obtain passwords of systems, accounts and networks. The attacker tries so many possible password combinations until he finally succeeds in identifying the correct password.
For this reason, the first suggested solution to protect against brute force attacks is to use complex and long passwords. Of course, it is better to use a combination of strategies such as limiting unsuccessful logins, hashing, implementing captcha and two-factor authentication to create more cyber security.
Additionally, organizations can test network security using common brute force attack tools such as Aircrack-ng, Hashcat, L0phtCrack, and John the Ripper.
What are your recommended strategies to deal with brute force attacks? Share your thoughts with us.