What is Brute Force Attack? | How to prevent? | Effects, How it Works?

Cyber security has become one of the most rigid industries in the last decade while simultaneously being the most challenged.

With every aspect of corporate culture going online and embracing cloud computing there is a plethora of critical data circulating through the internet, all worth billions of dollars to the right person.

Increasing benefits require more complex attacks and one of these attacks is a brute force attack.

A brute force or known as brute force cracking is the cyberattack equivalent of trying every key on your key ring and eventually finding the right one. Brute force attacks are simple and reliable there is no prior knowledge needed about the victim to start an attack.

Most of the systems falling prey to brute force attacks are actually well secured. Attackers let a computer do the work that is trying different combinations of usernames and passwords until they find one that works.

Due to this repeated trial and error format, the strength of password matters a great deal, although with enough time and resources brute force will break a system since they run multiple combinations until they find the right passcode.

What is Brute Force Attack?

A brute force attack is also known as an exhaustive search is a cryptographic hack that relies on guessing possible combinations of targeted passwords, until the current password is discovered.

It can be used to break into online accounts, encrypted documents, or even network peripheral devices.

The longer the password the more combinations that will need to be tested. A brute force attack can be time-consuming and difficult to perform if methods such as data obfuscation are used and at times downright impossible. 

However, if the password is weak it could merely take seconds with hardly any effort.

Dictionary attacks are an alternative to brute force attacks where the attacker already has a list of usernames and passwords that need to be tested against the target. It doesn't need to create any other combinations on its own.

Dictionary attacks are much more reliable than brute force in a real-world context but the usefulness depends entirely on the strength of passwords being used by the general population.

How does Brute Force-Force Work?

There is a three-step process when it comes to brute forcing a system.

1. We have to settle on a tool that we are going to use for brute-forcing

There are some popular names on the market like a hash cat, hydra, and john the ripper. While each of them has its own strength and weaknesses each of them perform well with the right configuration. 

All of these tools come pre-installed with certain Linux distributions that cater to penetration testers and cyber security analysts like Kali Linux and parrot security.

2. After deciding what tool to use we can start generating combinations of alphanumeric variables whose only limitation is the number of characters

For example, while using hydra, a single 6-digit password will create 900 000 passwords with only digits involved. Add alphabets and symbols to that sample space and that number grows exponentially. The popular tools allow customizing this process.

Let's say the hacker is aware of the password being a specific 8-digit word containing only letters and symbols; this will substantially increase the chances of being able to guess the right password.

Since we remove the time taken to generate the longer ones. We omit the need for including digits in such combinations.

These small tweaks go a long way in organizing an efficient boost force attack since running all the combinations with no filters will dramatically reduce the odds of finding the right credentials in time.

3. Trying to run the password through the service/ file for testing

In the final step,, we run these combinations against the file or service that is being broken. 

We can try and break into a specific encrypted document, a social media account, or even devices at home that connect to the internet.  For example Wifi Router

The generated passwords are then fed into the connection one after the other. It is a long and arduous process but the work is left to the computer other than someone manually clicking and checking each of these passcodes.

Any password that doesn't unlock the router is discarded and the brute force tool simply moves on to the next one, this keeps going on until we find the right combination which unlocks the router.

Sometimes reaching the success stage takes days and weeks which makes it cumbersome for people with low computing power at their disposal.

However the ability to crack any system in the world purely due to bad password habits is very appealing and the general public tends to stick with simple and easy-to-use passwords like 123…, password, etc.

Effects of Brute Force Attack

• Access to personal laptop/mobile

A hacked laptop or mobile can have social media accounts logged in, giving the hackers free access to the victim's connections. 

It has been reported on multiple occasions where compromised Facebook accounts are sending malicious links and attachments to people on their friend lists.

• Malware infusion and ransomware attacks

One of the significant reasons for hacking, malware infusion is best done when spread from multiple devices similar to distributing spam.

This reduces the chance of circling back the source to a single device that belongs to the hacker, once brute-forced a system can spread malware via email attachments, sharing links, file upload via FTP, etc.

• Theft of personal data for nefarious purposes

Personal information such as credit card data, usage habits, private images, and videos are all stored in our systems be it in plain format or root folders. 

A compromised laptop means easy access to this information that can be further used to impersonate the victim regarding bank verification among other things.

• Distributing spam with hacked machines

Once a system is hacked it can also be used as a mail server that distributes spam across lists of victims.

Since the hacked machines all have different IP addresses and mac addresses, it becomes challenging to trace the spam back to the original hacker.

With so many harmful implications arising from a brute force attack, it's imperative that the general public must be protected against such.

How to Prevent Brute Force Attacks

1. Use complex alphanumeric passwords

 

Using passwords consisting of alphabet letters and numbers have a much higher chance of withstanding brute force attacks thanks to the sheer number of combinations they can produce.

The longer the password the less likely it is that a hacker will devote the time and resources to brute force them.

Having alphanumeric passwords also allows the user to keep different passwords for different websites, this is to ensure that if a single account or password is compromised due to a breach or a hack the rest of the accounts are isolated from the incident.

2.  Using two-step of verification

Two-factor authentication involves receiving a one-time password on a trusted device before a new login is allowed. 

This OTP can be obtained either via email, SMS, or specific 2fa applications like authy and aegis. 

Email and SMS-based OTPs are considered relatively less secure nowadays due to the ease with which sim cards can be duplicated and mailboxes can be hacked.

Applications that are specifically made for 2fa codes are much more reliable and secure.                    

3. Captcha during login action

Captchas are used to stop bots from running through web pages precisely to prevent brute-forcing through their website.

Since brute force tools are automated, forcing the hacker to solve captcha for every iteration of a password manually is very challenging. 

The capture system can filter out these automated bots that keep refreshing the page with different credentials, thereby reducing the chances of brute force considerably.

4. Limited no. of login attempts

A definite rule that locks the account being hacked for 30 minutes after a specific number of attempts is a good way to prevent brute force attempts.  

Many websites lock accounts for 30 minutes after three failed password attempts to secure the account against any such attack on an additional note.

Some websites also send an email instructing the user that there have been three insecure attempts to log into the website.