- Brute force is an attack technique that involves an attacker attempting to try various username - password combinations to break into accounts.
- Some of the widely used brute force attack tools include Aircrack-ng, John the Ripper, L0phtCrack, and RainbowCrack.
Brute force is an attack technique that involves an attacker attempting to try various username - password combinations to break into accounts. It is a method used by attackers to gain unauthorized access to user accounts and steal personal information, financial information, and more.
It is a time-consuming method as it requires constant trial & errors and repetitive attempts of trying various password combinations.
How to perform brute force attacks?
Attackers use automated software tools to generate a large number of consecutive guesses as to the value of the targeted password. The software tools use computing to systematically check password combinations until the correct one is identified. Some of the widely used brute force attack tools include Aircrack-ng, John the Ripper, L0phtCrack, and RainbowCrack.
Types of brute-force attacks
- Dictionary attacks - Dictionary attacks, also known as Hybrid brute force attack is the most commonly used brute force attack. It uses a list of words in the dictionary or the commonly used passwords to crack passwords.
- Reverse brute force - Reverse brute force attacks will reverse the attack technique by starting with the known password and trying it against a list of possible usernames.
- Credential Stuffing - In Credential Stuffing attack, attackers use usernames-passwords combinations leaked at other sites to gain illegal access on user accounts.
Example of brute force attacks
Example 1 - Iridium threat group used brute force attacks to target high-profile targets
In March 2019, Iran hacking group Iridium leveraged brute force attacks to target numerous government agencies, oil and gas companies. Using brute force attacks, the threat group has stolen millions of data from a major software company that handles sensitive computer projects for the White House communications agency, the U.S. military, the FBI and many other American companies.
Example 2 - StealthWorker malware campaign
In March 2019, researchers observed a new campaign that distributed the StealthWorker malware on Windows and Linux systems. In this campaign, attackers leveraged the brute-force only approach to target a vulnerable host with weak credentials and compromise the target machine. Once compromised, the StealthWorker malware created scheduled tasks on both Windows and Linux to gain persistence.
How to stay protected from such attacks?
- To stay protected from such attacks, it is always recommended to use strong, complex, lengthy, and unique passwords that are difficult to crack.
- It is best to use two-factor authentication while logging in to accounts.
- It is recommended to always log out after the session is complete.
- Experts recommend periodically rotating passwords and never reuse the same password across multiple accounts.
- It is best to limit login attempts in order to prevent brute-forcing.
- It is also recommended to implement captcha to avoid stop brute force attacks.