With so many services and websites getting hacked over the past few years, it makes you wonder about the security techniques employed by the corporation to avoid this and the multitude of ways to bypass such methods. There have been multiple well-known attacks that target poorly configured systems, like ransomware attacks, supply chain attacks, and even malware infusion. A general question that arises is regarding what is a brute force attack and how it can ransack even the most secured databases around the world.
Let us begin this lesson by learning where brute force attacks are applicable.
Where Are Brute Force Attacks Used for?
The main argument for using brute force hacking over other procedures is the zero-knowledge approach. It means the hacker doesn’t need to have any prior knowledge of the system being hacked. A victim can have the most secure password and still be caught in the line of fire. Brute force attacks run every single combination of numbers and characters available, so irrespective of how secure user credentials are, given the time and processing power, they will get cracked. As we will learn later, techniques such as two-factor authentication and limiting login attempts save grace against brute force attacks.
Let’s learn about what is a brute force attack in detail.
What Is a Brute Force Attack?
A brute force attack generates multiple strings of alphanumeric characters that can be used as passwords. These strings then run against the file/service being cracked to find the correct password. Brute force attacks can be used against encrypted files, user account credentials, and even wireless networks with their passwords. There is no particular constraint when it comes to brute force mechanisms. We can generate numbers, alphabets and symbols to guess passwords of any length possible. Granted, the longer and more complicated passwords require much more time and effort to bear fruit.
Now that you have understood what is a brute force attack, let’s learn about how it’s supposed to work.
How Does Brute Force Work?
There are three distinct phases of a brute force attack.
Choosing a Tool
Choosing a tool that can brute force through passwords and keys is the primary requirement. Multiple frameworks are available in the market like Hydra, John the Ripper, and Hashcat that can brute force through anything, starting from encrypted documents to secure web forms.
We have to create password combinations using the tools above. These can be of any length that we want, along with the type of character we need to try. For example, just a single six-digit password can have 900000 combinations when using just numbers. Add alphabets and special characters to the mix, and we have a load of passwords to test.
Testing Generated Passwords
Let’s say we are looking for the password to a Wi-Fi router, and we know the password is six characters. We have already generated some combinations of these passwords in the last phase, so we run them into the Wi-Fi router to check if any of them are valid. We keep trying to connect with each generated password until one of them eventually works.
In the next section of our article on what is a brute force attack, let’s look at its harmful effects from a victim’s perspective.
Effects of Brute Force Attacks
- Distributing Spam: Once a system is hacked, it can be used as mail servers that distribute spam across lists of victims. Since the hacked machines have different IP addresses and MAC addresses, it becomes challenging to trace the spam back to the original hacker.
- Theft of Personal Data: 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 critical information that can be further used to impersonate the victim regarding bank verifications, among other things.
- Personal Device Breach: The hacked laptop or mobile can have social media accounts logged in, giving the hackers free access to the victims’ connections. It has been reported on multiple occasions that compromised Facebook accounts were sending malicious links and attachments to people on their friend list.
- Malware Infusion: Multiple devices compromised due to brute force attacks can be used to spread malware. This reduces the chance of circling back the source to a single device belonging to the hacker. Once brute-forced, a system can spread malware via email attachments, sharing links, file upload via FTP, etc.
Knowing about the problems faced by the victims can also help us formulate some ways to battle brute force attacks at a system level. Let’s learn about some of these techniques.
Precautions Against Brute Force Attacks
- Complex Passwords: Using passwords consisting of alphabets, letters and numbers have a much higher chance of withstanding brute force attacks, thanks to the sheer number of combinations they can produce.
- Using 2FA: Two-factor authentication involves receiving a one-time password (OTP) on a trusted device before allowing a new login to succeed. This OTP can be obtained either via email, SMS or specific 2FA applications like Authy and Aegis.
- Captcha during login: Captchas are used to stop bots from running through webpages, 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 challenging.
- Limited 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.
To better understand how we go ahead with brute-forcing passwords, let’s take a look at a demo that explains what is a brute force attack, in a step-by-step format.
Demo of Brute Force Mechanism
The world has gone wireless. With Wi-Fi taking the reins in every household, it’s natural that their security will always be up for debate. To further test their security index and understand brute force attacks, we will attempt to break into the password of a Wi-Fi router. For that to happen, we first need to capture a handshake file, which is a connection file from the Wi-Fi router to a connecting device like a mobile or a laptop. The operating system used for this process is Parrot Security, a Linux distribution catered to penetration testers. All the tools being used in this demo can be found pre-installed on the operating system.
1. We use an external network adapter in monitor mode, which is necessary to capture wireless transmission data over the air. We use a tool called Airgeddon to select a network to hack.
2. In this case,we are going for the network Jio 24 as it is the router that we have permission to break into for learning purposes. Next, we use the same tool to send de-authorization attacks that kick all connected devices out of the network for a split second, which force them to initiate a connection request again. This is done to capture the handshake file while they are reconnecting.
As per the image above, we can grab a WPA Handshake for the network Jio 24.
3. Once the handshake capture file is obtained, we pass the file to a brute force tool like Aircrack in our example.
As per the image above, the brute force tool tests passwords starting from combining a couple of alphabets to its very end phase, where all numbers, symbols and alphabets are involved. As evident from the time and speed mentioned, this is a resource-intensive process that will eventually guess the correct password for the Wi-Fi router when given the time.
With that, we reach the end of the article on what is a brute force attack.
How Can Simplilearn Help You?
Brute force attacks are widespread in today’s day and age, where the general public refrains from using complex passwords for their online and offline accounts. However, it’s just a single drop in the ocean of cyberattacks that plague the online world and require protection.
Simplilearn provides a "Cybersecurity Expert" course that focuses on such cybersecurity techniques and how to protect yourself from such attacks. The course is recommended for people looking to join the cybersecurity industry, as it covers basic and advanced modules, such as cryptography, penetration testing, and application security, that cater to beginners and professionals alike.
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In today’s lesson on what is a brute force attack, we learned about the workings of brute force attacks, their consequences, and ways to prevent such breaches. We also saw how to run brute force attacks on encrypted files, such as a handshake capture to get the original password.
If you are keen on learning more about Cyber Security and Ethical Hacking, do check out our Cyber Security Expert Master’s Program that will equip you with the skills needed to become an expert in this rapidly growing domain. You will learn comprehensive approaches to protecting your infrastructure, including securing data and information, running risk analysis and mitigation, architecting cloud-based security, achieving compliance, and much more with this best-in-class program.
If you have any queries regarding this topic, feel free to ask them in the comment section below, and we will be happy to answer.