With a brute force attack, a hacker aims to crack passwords. With the help of an algorithm, various character combinations are tried out in a very short time. For example, a 7-character password – consisting of one capital letter and six lower-case letters – can be cracked in around nine minutes.
A brute force attack is a method used to decrypt passwords or other access codes by trying all possible combinations until the right one is found. This type of attack does not rely on vulnerabilities in the system or complicated techniques such as social engineering; instead, it relies on raw computing power to try a variety of possibilities.
How a brute force attack works
The attack is usually carried out by specially programmed algorithms that can quickly and automatically test millions to billions of combinations. Depending on the length and complexity of the password and the computing power of the attacking computer, this process can take anywhere from seconds to several years. In your example, a 7-character password with one capital letter and six lower-case letters, such an attack only takes a few minutes.
Types and targets of brute force attacks
There are different variants of the brute force attack:
- Simple brute force attacks: This involves trying every possible combination without considering the likelihood that certain passwords could be used more frequently.
- Dictionary attacks: Here, a “dictionary” of frequently used passwords, such as “123456”, “password123” or similar combinations, is tested first to save time.
- Hybrid attacks: These combine the dictionary and brute force approaches to vary popular passwords, e.g. by adding numbers or special characters to common passwords.
The targets of such attacks are frequent:
- Privacy violations by accessing personal data,
- Financial loss due to intrusion into bank accounts or other financially relevant access,
- Sabotage or espionage, especially attacks on company networks.
Countermeasures
There are various defenses against brute force attacks:
- Complex passwords: Longer and more complex passwords consisting of upper and lower case letters, numbers and special characters make brute force attacks more time-consuming and expensive.
- Limited login attempts: Many systems limit the number of possible failed attempts, which prevents endless combinations from being tested.
- Multi-factor authentication (MFA): Even if the password is cracked, MFA ensures that a second confirmation is still required.
- CAPTCHAs: These “I-am-not-a-robot” tests slow down automatic programs, as the attacker often has to intervene manually.
In summary, a brute force attack is one of the most basic but effective techniques for cracking passwords if no suitable protective measures are taken.
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