Brute Force Attacks

When I was a kid, I found an old briefcase in my father’s stash. It was locked with a double 3-digit combination. The secrecy of its contents made me more curious and determined. My childish mind whispered, “Why not try all possible combinations, one by one? Start with ‘000-000’, then ‘000-001’, then ‘000-002,’ and so on…”

It felt like an adventure. I didn’t know how many combinations there were or how long it would take, but I had time, curiosity, and persistence on my side. In hindsight, my innocent determination to crack the briefcase reveals a universal truth: if given the tools, time, and motivation, people will try to bypass security to uncover secrets.

Now, imagine replacing that briefcase with a modern information system, the kind that holds the crown jewels of our civilization—financial records, intellectual property, medical data, national security secrets. And replace the naïve curiosity of a child with the calculated ambition of a malicious hacker who has the tools, skills, and persistence to break in.

Brute force attacks are a common cybersecurity threat where attackers systematically attempt to guess login credentials or encryption keys by trying various combinations until the correct one is found. These attacks can be highly effective against weak passwords and inadequate security measures.

Types of Brute Force Attacks

Simple Brute Force Attack

This basic type uses automation and scripts to guess passwords by trying every possible combination of characters. These attacks can make hundreds of guesses per second, potentially cracking simple passwords in minutes17.

Credential Stuffing

Attackers use stolen login credentials from data breaches to attempt access to other accounts where users have reused their credentials.

Dictionary Attack

This method uses a premade list of common words and phrases, often with slight variations, to guess passwords.

Hybrid Brute Force Attack

Combining dictionary and simple brute force attacks, this method starts with common words and then uses brute force to guess additional characters or numbers.

Reverse Brute Force Attack

Starting with a known password, often obtained through a breach, attackers search for matching login credentials using lists of usernames.

Tools for Brute Force Attacks

Attackers typically use automated software or scripts to perform brute force attacks. These tools can rapidly generate and test multiple combinations of passwords, usernames, or session IDs. A web automation library like Selenium, or Robot Framework also highly useful among software testing and automation. Security profesionals may use “Aircrack-ng”, “Hashcat”, “John the Ripper”, “Ophcrack”, “THC Hydra” to streghten security of systems.

Prevention Strategies

1. Enforce Strong, Unique Passwords: Implement policies requiring long, complex passwords that are unique for each account.
2. Implement Multi-Factor Authentication (MFA): Require additional verification methods beyond just passwords.
3. Limit Login Attempts: Set restrictions on the number and frequency of login attempts.
4. Monitor and Analyze Login Activity: Look for unusual patterns or suspicious IP addresses attempting to log in.
5. Use CAPTCHAs: Implement challenges that are difficult for automated programs but easy for humans.
6. Implement Account Lockouts: Temporarily lock accounts after a specified number of failed login attempts.
7. Employ Passwordless Authentication: Use biometric identifiers, magic links, or passkeys instead of traditional passwords.
8. Regular Security Audits: Conduct vulnerability assessments and penetration testing to identify weaknesses.

Real-Life Examples

1. LinkedIn (2012): Hackers breached LinkedIn’s security, gaining access to millions of user passwords through a combination of social engineering and brute force attacks.
2. Dunkin’ Donuts (2015): Attackers used brute force methods to access about 19,715 user accounts within five days, stealing significant sums of money. This resulted in $650,000 in fines and damages for the company.
3. GitHub (2013): A brute force attack targeted GitHub users, using nearly 40,000 individual IP addresses to avoid detection. The company promptly informed users and required password updates.
4. T-Mobile (2021): A hacker used a combination of brute force attacks and other techniques to gain access to T-Mobile’s servers, leading to a data breach that exposed the personal information of around 40 million customers.
5. Russian Military Targeting Microsoft Accounts (2020): Members of the Russian military reportedly used brute force attacks to target over 200 organizations, including advocacy groups, political parties, and consultants, to gain access to their Microsoft Office 365 accounts.

These examples highlight the persistent threat of brute force attacks and the importance of implementing robust security measures to protect against them.

Lesson in Cybersecurity: The Briefcase and the Hacker

1. The Power of Brute Force:
   • Just as I tried to brute-force the briefcase by going through all combinations, attackers can use brute force attacks to guess passwords. Modern computers can try billions of password combinations in seconds.
   • The Lesson: Use strong, complex passwords that combine uppercase, lowercase, numbers, and special characters. More importantly, implement rate-limiting or account lockouts to stop relentless attempts.
2. Motivation Drives Persistence:
   • My curiosity to discover what was inside the briefcase parallels a hacker’s drive to exploit vulnerabilities. Whether it’s money, sensitive data, or fame, the motivation fuels the effort.
   • The Lesson: Assume that any weakness in your system will be targeted. Perform regular penetration testing and vulnerability assessments to identify and address gaps before attackers exploit them.
3. Underestimating the “Enemy”:
   • My father probably didn’t expect a little kid to try cracking his briefcase lock. Similarly, many organizations underestimate the skill and persistence of attackers or assume they’re not a target.
   • The Lesson: Security isn’t just about stopping high-profile attackers. Many breaches start with small, overlooked weaknesses, like an employee’s weak password or an unpatched system.
4. Tools Make the Task Easier:
   • Imagine if I had a tool to test all combinations automatically. What took me hours as a child could have been done in seconds with the right equipment.
   • The Lesson: Attackers use sophisticated tools, such as password-cracking software, malware, and phishing kits. Defenders must counteract with tools like multi-factor authentication (MFA), encryption, and intrusion detection systems (IDS).
5. The Importance of Multi-Layered Security:
   • The briefcase had two locks, which increased the difficulty but wasn’t insurmountable. Systems that rely on a single line of defense—like passwords alone—are similarly vulnerable.
   • The Lesson: Implement defense in depth by layering security controls—firewalls, encryption, MFA, monitoring, and regular audits—to make it harder for attackers to succeed.

Eventually, I opened the briefcase. Inside, I found some old family documents, my fathers old stamp collections, some old letters and keepsakes. They were precious in their own way, but not the treasure trove I had imagined. The secrecy had fueled my curiosity far more than the actual contents justified.

Similarly, attackers often breach systems and find mundane or useless data. But the cost of the breach—damaged reputations, stolen identities, or compromised security—can be catastrophic.

Final Cybersecurity Takeaways:

• Stay Vigilant: Attackers are curious, motivated, and persistent, just like that child determined to open a locked briefcase.
• Strong Security Practices Matter: Passwords, MFA, and encryption are the modern equivalents of multi-layered locks.
• Educate and Adapt: The best defense is not just technical—it’s also training people to recognize phishing, avoid unsafe links, and report suspicious activity.

Protect your systems as if they hold your most valuable treasures, because to someone out there, they do.