Cyber Security – Brute Force vs Password Spray. What’s the difference?
In the world of cyber security, attackers have a multitude of tools at their disposal to breach user accounts. Two common methods of attack are Brute Force and Password Spray. While both leverage automation to gain unauthorised access, they differ in their approach.
This article covers both strategies and how to defend against them.
Brute Force – What is a Brute Force attack?
A common attack based on a trial-and-error method used to discover the correct credential (username and password) combination. The process is akin to trying every possible key to open a lock until the correct one is discovered.
The Brute Force Strategy:
- Target Identification: The attacker identifies the target system or data they want to access. This could be a website, a network server, encrypted files, or any other system protected by passwords or encryption.
- Automation of Brute Force: Attackers use software to automate the guessing process. This software can attempt millions of combinations per second.
- Different Combinations: The software works its way through all possible combinations of characters depending on the password length and complexity. For simple passwords, it might try every letter and number combination. For more complex passwords, it might include symbols and special characters.
- Dictionary Attacks: In some cases, attackers might use dictionaries or leaked password lists as a starting point, focusing on commonly used passwords or passwords based on personal information about the target.
- Detection Avoidance: To avoid easy detection, attackers may employ various techniques such as slowing down the rate of password attempts and / or using multiple IP addresses or compromised systems to distribute the attack.
Where Brute Force can be effective:
- Weak / Simple Passwords: Short passwords with only letters or numbers are particularly susceptible as there are fewer combinations to try.
- Common Password Patterns: If users include predictable elements like birthdays or pet names, attackers can incorporate these patterns into their scripts and attempts.
- Lack of Multi-factor authentication (MFA): MFA is key to Brute Force protection.
How to defend against Brute Force attacks:
- Strong Password Policies: Ensure you enforce strong password policies with minimum password length requirements and a mix of character types (longer passwords, combination of letters, numbers, and special characters).
- Multi-factor Authentication (MFA): Implement MFA to make it more difficult for attackers to gain access, even if they obtain the correct credentials.
- Account Lockouts: Configure account lockouts after a specific number of failed login attempts to stop automated guessing.
- Intrusion Detection Systems: Ensure you are running automated intrusion detection to detect and respond quickly to suspected Brute Force activity.
Password Spray – What is a Password Spray attack?
An attack where the attacker tries a single (often commonly used) password against many accounts. By using commonly used or easily guessable passwords, the attacker increases their chances of success. A spray attack typically uses a list of known usernames and tries a small set of commonly used passwords against each username.
The Password Spray Strategy:
- Credential Gathering: Attackers often obtain lists of usernames through data breaches or leaked information. They might also use common usernames or try dictionary attacks to generate a list of usernames for a specific service.
- Password Selection: Instead of trying random passwords, attackers leverage lists of commonly used passwords, leaked passwords from other breaches, passwords based on popular culture, or simple patterns – e.g. password123.
- Automated Attacks: The attacker uses automated tools to try the chosen password list against the list of usernames on the target system. This is often scripted to bypass manual effort and appear like legitimate login attempts.
Where Password Spray can be effective:
- Weak Password Policies: Organisations or systems with weak password policies allowing users to create easily guessable passwords.
- Reusing Passwords: Many users reuse the same password across multiple accounts. If one account on a compromised service used that password, the attacker may gain access to other accounts where the victim reused it.
- Bypasses Lockouts: Unlike brute-force attacks that focus on a single account and risk triggering lockouts, password spraying distributes attempts across many accounts, making it harder to detect and avoiding immediate account lockouts.
- Poor Intrusion Detection Systems: A lack of, or poorly configured, detection systems.
- Lack of Multi-factor authentication (MFA): MFA is key to Password Spray protection.
How to defend against Password Spray attacks:
- Strong Password Policy: Enforce strong password policies that encourage users to create unique and complex passwords for every account.
- Password Education: Teach users about the importance of choosing strong, unique passwords or phrases that are not easily guessed or found in password dictionaries.
- Multi-factor Authentication (MFA): Implement MFA to make it more difficult for attackers to gain access, even if they obtain the correct credentials.
- Detection systems to monitor for unusual login patterns: Use monitoring tools to detect unusual login patterns, such as numerous successful logins with specific (common) passwords.