A strong password safeguards our data online. Those who fail to adequately protect their accounts make it easier for cybercriminals to gain unauthorised access to sensitive information. Simpler passwords are often quickly guessed through trial and error. However, it doesn’t always stop at manual attempts. Hackers utilise brute-force attacks, employing immense computing power to crack passwords with (literally) brute force. Read on to learn in detail how such an attack works, how to identify it, and how to protect yourself. Discover how you can browse even more securely in future and shield yourself from online threats with the help of Avira Free Security.
Definition: What is a brute-force attack?
A brute-force attack is an attempt to deliberately gain unauthorised access to a system or account protected by a password. To crack the password, every possible combination of numbers, letters, and special characters is systematically tried. This can be done manually by an attacker or through the use of software. When software is employed, the rule is: The more computing power the criminals have, the more combinations they can attempt.
As a general rule: The more complex, longer, and random a password is, the longer the process takes. Strong passwords and server-side security measures significantly reduce the risk of a brute-force attack being successful.
What are the attackers’ goals?
Cybercriminals have numerous ways to achieve their malicious aims. Brute-force attacks primarily aim to gain unauthorised access to accounts, systems, or documents. Once the attackers have access to the data, further criminal acts typically follow.
The attackers often pursue one or more of the following goals:
- Access to sensitive personal information (e.g. email, banking, shopping accounts)
- Access to sensitive business information (e.g. customer data, financial reports, business plans)
- Manipulation of data and systems to render them unusable or to create chaos
- Financial gain through unauthorised transfers, extortion, or the sale of personal data
- Integration of computers into a botnet
- Dissemination of social or political messages (“hacktivism”)
What types of brute-force attacks are there?
Cybercriminals employ various methods to carry out a brute-force attack. Here are the most common ones:
- Classic brute-force attack: The attacker randomly attempts all possible combinations, from very simple ones (e.g., 0000, abcde) to highly complex ones (e.g., jShdWRsJfGj). With the help of an automated tool, the number of combinations tested multiplies into the millions very quickly.
- Simple “dictionary attack”: The attacker uses an existing list of commonly used passwords. Many people opt for simple passwords for convenience, such as 123456, admin, or qwerty. In such cases, access can often be achieved within seconds.
- Hybrid attack: This method combines the classic brute-force attack with a dictionary attack. The attacker starts with a list of popular passwords and enhances them by adding numbers or special characters.
- Reverse brute-force attack: Instead of guessing the password, the attacker starts with a commonly used password and tests it against multiple usernames until a match is found.
- Credential stuffing: This approach uses stolen username and password combinations from previous data breaches to log into other platforms. It is especially effective when users reuse the same passwords across different services.
- Offline brute-force attack: In this case, attackers gain access to a file containing encrypted password hashes. Without needing to interact with the live system, they have unlimited attempts to decrypt the hashes.
- Online brute-force attack: Here, attackers test different passwords directly in the login field of the targeted website. Countermeasures like captchas and limits on login attempts often block such attacks.
- Distributed brute-force attack: Similar to a botnet or a DDoS attack, this method spreads the brute-force process across multiple devices to significantly reduce the computational load on any single device. By distributing resources, attackers can test even more combinations in a shorter amount of time.
What are the signs of a brute-force attack?
A brute-force attack often goes unnoticed because it doesn’t leave visible changes on a website. However, it does leave traces “behind the scenes.” Website operators can detect such attacks or similar ones by examining log data and server information.
Typical signs of a brute-force attack include:
- Significant increase in login attempts: Many failed attempts to access an account occur in a short time.
- Unusual network activity: A sudden spike in incoming traffic, particularly targeting login and authentication servers.
- Suspicious activity from a single IP: A single IP address repeatedly tries different usernames or passwords.
- Dubious IP address locations: Access from IPs in unusual regions that differ from the typical locations of legitimate users.
- A large number of locked accounts: Multiple accounts become locked due to repeated failed login attempts.
- Unusual server overload: Servers and databases processing incoming requests become overwhelmed, leading to slower response times.
How to protect yourself against attacks
The best defence against a brute-force attack is a secure password, but protection doesn’t stop there. Several other measures can help prevent such attacks from succeeding:
- Password length: The longer your password, the more character combinations a hacker and their tools will need to try.
- Password complexity: Using a mix of letters, numbers, and special characters makes it even harder for attackers. Every additional number, letter, or symbol makes the attack less likely to succeed.
- Multi-factor authentication (MFA): Adding an extra layer of authentication significantly enhances account security. Most major websites with user accounts now offer two-factor authentication, which supplements login credentials with a time-sensitive code.
- Website restrictions: As a website operator, you can implement measures to thwart attacks. These include time delays between login attempts, CAPTCHA challenges, and account lockouts after a certain number of failed attempts.
Using a password manager eliminates the need to remember complex, unique passwords for each site. This tool securely stores all your login credentials and automatically fills in login forms for you. Convenience no longer needs to influence your choice of a secure password.
Tip: For guidance on creating a strong password, see our article on How to generate a strong password.
How to browse even more securely with Avira Free Security
The internet offers countless opportunities, but it’s also exploited by cybercriminals for illegal activities. As an internet user, you should protect yourself against brute-force attacks and unauthorised access with a strong password and multi-factor authentication. To ensure protection against harmful malware and spyware, we recommend Avira Free Security.
With our all-in-one solution, you’ll benefit from reliable real-time virus protection and the ability to browse safely and anonymously, even on public networks. The integrated VPN allows you to surf unnoticed, even on unsecured Wi-Fi connections (such as in restaurants or cafés), keeping your true identity hidden from third parties. Additionally, you can access global media content from providers like Netflix, even if it’s usually restricted in your region. Secure your computer or smartphone today with Avira Free Security.