Cyber Threat: Ataque de força bruta

O que é um ataque de força bruta?

A brute force attack is a cyber attack in which a cybercriminal systematically attempts a high volume of username and password combinations until they find a match. Unlike attacks that exploit software vulnerabilities, brute force attacks target weak or reused passwords. Improving password security and authentication methods has become essential for every user and organization to protect their data and systems.

Illustration of a login screen with red-highlighted username and password fields, symbolizing repeated login attempts. The dark interface and red tones represent the threat of a brute force attack, where attackers try multiple password combinations to gain unauthorized access.

How do brute force attacks work?

Brute force attacks rely on automated tools to generate and test millions of username and password combinations in rapid succession until they find a match. Cybercriminals use stolen credential databases, lists of commonly used passwords and algorithmic variations to mimic how people typically create passwords. Once a match is found, cybercriminals gain access to their victim's account, enabling data theft, privilege escalation or fraud. Because these attacks can be distributed across large botnets, their activity can blend into normal traffic.

Motives behind brute force attacks

Dark login interface with red-highlighted username and password fields and a cursor hovering over the password box, symbolizing the unauthorized capture or theft of sensitive login credentials.

Steal sensitive data

Dark-themed pop-up window with a glowing red button and a cursor hovering over it, symbolizing a malicious advertisement. The design represents exploit ads that trick users into clicking links that lead to malware or security breaches.

Exploit ads

Graphic of a laptop screen displaying a glowing red bug icon with a cursor pointing toward it, symbolizing malware spreading on a device.

Spread malware

Six common types of brute force attacks

Ataques de força bruta simples

Simple brute force attacks involve guessing every possible password combination until one works. They may be time-consuming, but they are highly effective against short or weak passwords.

Illustration of a browser window displaying multiple red password entry attempts connected by dotted lines, symbolizing a simple brute force attack where an attacker tries numerous password combinations to gain unauthorized access.

Ataques de dicionário

Dictionary attacks automate login attempts using lists of commonly used passwords or phrases. Instead of testing random character strings, cybercriminals prioritize likely options, reducing the time spent to find a correct match.

Graphic of a screen displaying a numbered list of password attempts, represented by red dots, symbolizing a dictionary attack where predefined passwords are systematically tested to gain unauthorized access.

Ataques de força bruta híbridos

Hybrid brute force attacks combine the coverage of simple brute force and the speed of dictionary attacks. They begin with common or leaked passwords, then substitute characters with numbers or symbols to mimic typical variations.

List of common password variations with one highlighted in red—'Password@123'—and marked with a warning icon. The image symbolizes a hybrid brute force attack, combining dictionary-based words with common character substitutions to guess passwords.

Sobrecarga de credenciais

Credential stuffing uses previously compromised credentials to attempt to log in across multiple platforms. If users reuse passwords, cybercriminals can quickly gain access to more accounts and escalate the impact of a breach.

Terminal window displaying repeated login attempts with HTTP POST requests, including multiple '401 Unauthorized' responses and one '200 OK' success. Below, a red warning highlights the password 'Password123!'—symbolizing a credential stuffing attack using reused login credentials across sites.

Ataques de força bruta reversos

Reverse brute force attacks start with a single common password, like “123456,” and attempt to match it against thousands of usernames. This exploits the prevalence of weak or common passwords to increase the chance of a successful login.

List of email addresses with one highlighted in red—laura@company.com—and paired with a weak password '123456' marked by a warning icon. The visual symbolizes a reverse brute force attack, where a common password is used across many usernames to find a match.

Pulverização de senhas

Password spraying targets many accounts using a small group of commonly used passwords. By limiting the number of login attempts per account, cybercriminals can avoid triggering lockout policies and security alerts.

List of email addresses with one—brian@company.com—highlighted in red. Three common passwords—'Welcome123!', 'Winter2024!', and 'Summer2025!'—are shown with warning icons. The image symbolizes a password spraying attack, where attackers try a few common passwords across many user accounts.

How to stay protected against brute force attacks

Use strong, unique passwords

Brute force attacks thrive on weak, reused passwords, so protecting your accounts with long, complex passwords and passphrases is a must.

Enable Multi-Factor Authentication (MFA)

MFA adds another layer of protection because even if a password is compromised, a cybercriminal cannot access your account without the second factor.

Monitor and automate threat detection

Security solutions can detect behavioral anomalies and trigger real-time alerts when suspicious login activity occurs, stopping brute force attacks before accounts are compromised.

Remove unused accounts

Orphaned or forgotten accounts are valuable to cybercriminals, making it crucial to audit all accounts and remove inactive ones. Enforce least-privilege access to reduce the risk of overprivileged accounts being exploited.

Encrypt credentials

Store passwords and authentication data in encrypted formats, both in transit and at rest, to stop cybercriminals from exploiting exposed credentials. Even if cybercriminals gain access to stored data, encryption makes it unusable and protected.

Limit and throttle login attempts

Implementing account lockouts reduces repeated failed login attempts, making brute force attacks more difficult to execute and easier to detect.

How Keeper^® protects you from brute force attacks

Keeper prevents brute force attacks by replacing weak and reused passwords with strong, unique ones for every account. With MFA support and advanced monitoring, Keeper prevents unauthorized access and alerts IT administrators about suspicious activity in real time. By combining zero-knowledge encryption with enforcement policies, Keeper helps both individuals and organizations prevent brute force attacks before they turn into full-scale data breaches.