Password cracking, or password hacking, is when attackers try to crack or guess a password to get unauthorized access to systems or data. Hackers use several types of tools and techniques, many of them automated, known as password crackers to speed up the process of accessing systems. With AI involved, these tools have become even faster and more efficient at cracking passwords. Beyond that, hackers often rely on malware, third-party breaches, or tools like Redline password stealers to get hold of compromised passwords.

Passwords are a critical part of security, helping to confirm that the right person has access to a resource, usually alongside a username. But compromised passwords are a big factor in security breaches today. For example, Google Cloud’s 2023 Threat Horizons Report found that 86% of breaches were tied to stolen credentials. This shows how common it’s become for attackers to focus on cracking passwords as they shift to identity-based attacks. Once they have access to accounts with high-level privileges, it’s easy for them to move around systems, crack more passwords, and access even more sensitive information.

Cracking passwords can take a few different forms, but it typically involves recovering encrypted passwords to gain access. Hackers use techniques like password guessing and password cracking, and while these terms are often mixed up, they’re actually different:

Password guessing: This is more of a trial-and-error approach, usually done online

Password cracking: Focuses on decrypting passwords offline

Both are essential for understanding how attackers break in, and why preventing cracking passwords is so important for staying secure.

When it comes to cracking passwords, hackers usually go about it in two main ways: online or offline attacks.

Online password attack

In this type of password attack a threat actor tries to guess the correct password by repeatedly attempting to log in directly on a website or app. Since they're doing this in real time on the server, it's slower because they’re limited by network speeds, and all the constant login attempts are noisy, making it easier for security teams to notice. Still, online attacks are common, especially when security measures aren't strict enough.

Offline password attacks

In this case, threat actors aren't trying to guess passwords live. Instead, they get hold of encrypted passwords, called password hashes, which are scrambled versions of the real password stored in a database. Once they have these, they can take their time working offline to crack them using special tools. Without the pressure of being detected, they can try out different cracking techniques, gradually decrypting the password hashes until they crack them. This approach is much sneakier and more effective, which is why offline attacks are such a big deal in cybersecurity.

One of the most straightforward and widely used methods of cracking passwords is simply guessing. In password guessing attacks, hackers rely on weak passwords, social engineering, and predictable patterns. Since most systems allow users to make a few wrong guesses without being locked out, attackers use this to their advantage. Let's break down some of the most common techniques used in password guessing attacks:

Random guesses

Random guessing involves attackers using predictable usernames (like email addresses) to target accounts. Once the username is known, they attempt to guess the password, often starting with common choices like "password" or variations of the user's personal information, such as birthdays, names, or hobbies. Although random guessing has a low success rate, it can still work when passwords are weak or based on easily accessible information found on social media or from previous breaches. Automated password cracking tools can boost the success of these attacks, especially if users practice poor password hygiene and reuse weak passwords across multiple sites.

Phishing

Phishing attacks are more about tricking users into voluntarily giving up their passwords than actually guessing them. Through fake emails, texts, or websites that mimic legitimate sources, hackers lure victims into entering their credentials. Phishing can be broad, like fake inheritance scams, or targeted, such as imitating a company’s password reset process. In either case, once the victim shares their password, the attacker gains immediate access.

Understanding these common password guessing techniques highlights why strong, unique passwords and security measures like multi-factor authentication are so important. Hackers rely on predictable behaviors and weak passwords, so using complex, randomized credentials and enabling extra layers of security can go a long way in preventing attacks.

Brute force attacks‍

Brute force attacks take password guessing to the extreme by trying every possible combination of characters until the correct one is found. While this method guarantees success eventually, it’s often time-consuming and inefficient, especially for longer, more complex passwords. A short password without special characters is more vulnerable, but as passwords grow in length and complexity, brute force attacks become impractical, even for powerful systems.

Credential stuffing

Credential stuffing doesn’t require guessing at all. Instead, hackers use stolen usernames and passwords from previous data breaches and attempt to log into other sites, hoping the user has reused their credentials. This technique leverages automation to test millions of login attempts and is only successful because many users reuse passwords across different sites. Without multi-factor authentication (MFA), credential stuffing becomes an easy and effective way for attackers to gain access to multiple accounts.

Password spraying

Password spraying is the reverse of brute force. Instead of attacking one account with many password guesses, the hacker attempts to log into many accounts using a few common passwords like "123456" or "Password1." This method avoids account lockouts by spreading out attempts over multiple users, making it harder to detect. This technique has gained prominence in recent attacks and can easily compromise accounts with weak or commonly used passwords.

Hybrid attacks

Hybrid attacks combine dictionary and brute force methods. For example, if a hacker knows a user's old password from a previous breach, they might try variations of it, adding numbers or special characters at the end. Since users often make small, predictable changes to their passwords after breaches, hybrid attacks can be highly effective at cracking newly updated passwords.

Rainbow table attacks

Rainbow table attacks target encrypted (hashed) passwords stored in databases. Instead of guessing passwords directly, hackers use precomputed tables of hashed passwords (rainbow tables) and compare them to the target hash. While time-consuming to create, rainbow tables can quickly crack weakly hashed passwords. However, these attacks can be thwarted if the password hashes are "salted" (adding random data to the hashing process), making the tables ineffective.

Dictionary attacks

A dictionary attack is a more automated method of password guessing. It uses lists of common words or phrases (like "baseball" or "qwerty") to try and crack a password. Attackers customize these word lists by adding numbers or special characters to match password complexity requirements, making the attack more effective. The downside is that dictionary attacks rely on real words, so they can be thwarted if the password is sufficiently complex or nonsensical. However, without account lockout settings or monitoring of failed login attempts, dictionary attacks can go unnoticed and be highly successful.

Use password managers & vaults – automate, don’t rely on memory

Relying on humans to manually manage passwords is risky and outdated. Instead, use password managers and vaults to store and secure credentials. Avoid keeping passwords in spreadsheets, documents, or even on paper. These tools follow best practices, auto-injecting vaulted passwords when needed and obscuring them from users like vendors, adding an extra layer of security. Personal password managers are great for everyday account passwords, but for more sensitive, privileged credentials—like SSH keys and DevOps secrets—organizations should use Privileged Password Management solutions. These tools are essential for protecting access in a zero trust environment and securing both privileged and general workforce passwords.

Identify and vault all passwords before granting access

Before granting access, ensure all passwords—whether for a human, machine, or application—are known, managed, and centrally vaulted. Documenting every asset that requires a password helps prevent inappropriate access and keeps credentials under tight control.

Generate strong, random, and unique passphrases

The strength of a password is critical to resisting cracking attempts. Use long, random passphrases of at least eight characters that combine upper and lowercase letters, numbers, and symbols. Avoid using dictionary words or anything personally identifiable. For sensitive accounts, follow the NIST recommendation of generating passphrases up to 64 characters, including spaces, for maximum security.

Encrypt passwords

Encryption is key to protecting passwords, even if they are stolen. Apply end-to-end encryption across all paths of network communication to keep passwords secure during transit. This includes ensuring your home WiFi network uses proper encryption to protect consumer devices from exposure.

Use unique passwords for every account

Never reuse passwords across multiple accounts. Using the same password everywhere creates a huge risk—if one account is compromised, hackers can easily gain access to others. By using unique passwords for each login, you minimize the potential damage from a breach.

Rotate and Expire Passwords as Needed

For personal accounts, frequent password changes are not necessary unless there’s evidence of compromise, according to NIST. However, for privileged accounts, regular rotation of passwords is essential. Consider using one-time passwords (OTPs) or dynamic secrets for high-risk accounts to ensure credentials expire after each use.

Strengthen security with Multi-Factor Authentication (MFA)

Single-factor authentication isn’t enough anymore, especially for privileged accounts and remote access. Adding MFA greatly strengthens security by requiring an extra layer of verification, such as a fingerprint or authentication app, to confirm the user’s identity. Some forms of MFA, like FIDO2, are stronger than others, and it's crucial to avoid pitfalls like MFA fatigue attacks.

Remove passwords when access Is no longer needed

Always remove access and change passwords when an employee or vendor leaves your organization. This prevents ex-employees or malicious actors from exploiting orphaned accounts or credentials that were left active. Regular deprovisioning ensures that only authorized users maintain access, keeping your systems secure.

Password cracking tools are essential for hackers aiming to crack passwords, particularly in offline attacks. These tools help automate the decryption of password hashes, working through potentially millions of plaintext combinations. They use advanced algorithms and machine learning techniques to break down encryption, making it easier to access compromised data. Here are some of the most widely used password cracking tools:

John the Ripper (JTR)

John the Ripper is one of the most well-established password cracking tools in existence. It’s command-based and works primarily on Linux and Mac OS, capable of automatically detecting and supporting a wide variety of hash types and encryption ciphers. JTR is popular because it's free, open-source, and highly flexible, though a "pro" version offers additional features such as an extensive wordlist and support for specific operating systems.

Cain and Abel

Cain and Abel, or simply Cain, is another prominent password cracking tool, this time designed for Windows users. It features a user-friendly graphical interface, making it accessible even to beginner hackers. Cain can recover passwords through various methods, including brute-force attacks, dictionary attacks, and decryption of encrypted data. Its simplicity and efficiency make it a popular choice for those looking to crack passwords on Windows systems.

Other common password cracking tools

Aside from John the Ripper and Cain, many other password cracking tools pose significant security risks. Some notable examples include:

Ophcrack: A password cracker that uses rainbow tables and brute-force techniques, available for Windows, macOS, and Linux systems.

Hashcat: Known for its high speed, Hashcat is a versatile tool that supports a wide range of hash types and attack methods.

THC Hydra: A powerful network logon cracker that supports multiple protocols, making it a useful tool for brute-forcing web-based logins.

Darktrace uses AI to detect and respond to suspicious behavior, like failed login attempts or unusual account activity, in real-time. It quickly identifies and blocks password cracking attempts, offering proactive protection across both cloud and on-premises networks while integrating with existing security systems.

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