What Is a Data Leak?

Cybersecurity Content Writer

“Data leak jeopardizes more than 150 million users.” “Hacker leaks 33 million usernames and passwords.” Sound familiar? As security technology advances and becomes more sophisticated, companies struggle to keep up with the latest requirements. Now hardly a day goes by that we don't hear about a data leak or a breach. Read on to find out how they differ and how you can prevent your company's data from leaking.

A data leak is a security incident in which private information becomes available to unauthorized persons. People may steal, accidentally transfer, or willingly give it away. Leaked data can be in digital (electronic files) or physical (documents, letters, pictures, devices) form. However, data leaks are not the same thing as data breaches.

Usually, data leaks happen because of poor security measures or someone's accidental actions. For example, security researchers from vpnMentor have been hunting for open databases for years. Whenever they manage to find one, it's called a data leak. Last month, they discovered that the Key Ring app used a misconfigured Amazon S3 bucket to store 44 million records, including people's IDs, insurance information, driver's licenses, and credit cards. Even if no malicious actors noticed it before them and the company took care to close the database, it's still classified as a data leak.

On the other hand, data breaches happen when a cybercriminal attacks a company or a database and manages to obtain secret information. They use DDoS attacks, malware, and social engineering to break the company's defenses. The results of data breaches and leaks are similar, but the methods differ.

Types of data leaks

  • Intentional data leak

    It might be an employee who sells the company's secrets or users' records for personal financial gain. It might also be a whistleblower who has moral objections to what they witness in the company they work for. Either way, they know what they are doing and usually try to remain anonymous.

  • Accidental data leak

    An unintentional leak could be as trivial as sending a confidential email to the wrong address. Leaving a database with your customers' data publicly accessible is also considered an accidental data leak. But the consequences ultimately depend on who got the email or found the loophole allowing them to access the database.

  • Outsider working to damage the company

    Sometimes people will look for gaps in your security to prove that they exist. They will not attack you openly. Instead, they will look for loopholes and bugs in the system that will allow them to access information that's not supposed to be accessible from the outside.

What type of data is at risk?

Cybercrooks look for sensitive information that can bring in a profit during a data leak. Usually, hackers are after personally identifiable information such as names, addresses, social security numbers, and credit card numbers.

When bad actors look to hurt a specific business, the information they look for might expand beyond personally identifiable data. For instance, hackers could steal sensitive company information such as internal communications and strategic plans. Trade secrets and intellectual property such as proprietary code and software can also be on a hacker's radar.

Today, data is paramount. And with the increasing frequency of cyberattacks, businesses have to take serious action to ensure the security of their data to thrive in the digital age.

How is the leaked data used?

Hackers can leverage leaked or stolen data in a variety of ways. At the end of the day, it all depends on the bad actors' end goal. Here are a few ways that exposed data can be used.

Social engineering

The information exposed in data breaches often includes personally identifiable information such as email addresses, and names. Hackers can use all that information in social engineering attacks such as phishing — a type of attack during which hackers send out fake emails that impersonate a reputable source to get the potential victim to download a malicious attachment or click on a dangerous link. Without the email address, names, and other sensitive data, hackers would be less successful in targeting and carrying out their attacks.


Doxing is an act of exposing personally identifiable information such as a person's name, home address, phone number, and other similarly sensitive information with malicious intent. After a successful data breach, hackers usually have more information than they need to dox a person.

Slowdown or disruption of business operations

A data breach can have a tremendously negative impact on the affected organization. According to the National Cyber Security Alliance, a whopping 60% of companies go out of business within six months after falling victim to a data breach.

Real-world examples of data leaks

Data breaches are more common than ever, and experts think that the frequency of such cyber incidents will only rise in the future. Here are a few major data breaches that had companies around the world on their toes:

  • Twitch

    In October 2021, Twitch — the game-streaming platform — revealed it had experienced a massive data breach. The hacker allegedly behind the breach exposed more than 100GB of sensitive data, which included the streamer's names, addresses, email addresses, and even earnings.

  • Experian

    In February of 2021, reports came out about the most significant data breach in Brazil's history, which exposed the sensitive information of more than 200 million people and 40 million companies. The likely culprit for the leak is Serasa Experian (a company providing information and data services). The exposed data included personally identifiable information such as dates of birth, full names, addresses, headshots, credit scores, income, and other financial information.

  • Facebook

    On April 3, 2021, a security expert discovered a massive data leak that affected 533 million Facebook users. Overall, the leak produced 2,837,793,637 data points. On average, hackers exposed at least five types of data per user, which included information such as phone numbers, full names, dates of birth, Facebook IDs, email addresses, and user bios.

How to prevent data leaks and breaches

To minimize the risk of a data leak, you should establish particular security practices and procedures in your company. Remember that you won't be able to control every little thing security-wise – you never know when you might become a cybercriminal's target. However, taking a few preventive measures will give you some peace of mind:

  • Control your data

    You must have backups of your data if something happens, but don't store unnecessary copies of sensitive data. Keeping it extra safe in one secure database instead of multiple terminals will lessen the chance of it leaking. Knowing and controlling who has access to what information is also essential. Employees should only be allowed to access the data they need for their work. This way, you can avoid accidents and intentional leaks.

  • Place restrictions on your employees’ emails

    You can set up Google Drive to notify your employees whenever they attempt to share the company's files with an outsider. Also, try using spam and phishing filters to cut the risk of successful social engineering attacks.

  • Train your employees

    A basic understanding of potential cybersecurity risks is essential for every person working in your company, especially if you handle sensitive data. Everyone from the receptionist to the head analyst should be aware of social engineering attacks, malware types, and internal security requirements. If they know and understand how much damage a data leak would do to the company, they are bound to be more careful.

  • Establish strong security measures in your company

    Use firewalls to protect your network and restrict specific traffic. Ensure you're safe from malware, like ransomware, spyware, or keyloggers. Use a VPN with robust encryption to ensure secure connections, especially if your employees often travel or work from home. Make sure they use strong passwords and two-factor authentication for their most sensitive accounts. Encourage using a password generator to create a complex password of at least 12 characters and a password manager to store them safely.

  • Prepare for the worst

    It's a good idea to have a response and damage control plan ready in case of a data leak. If you suffer from a cyberattack, every minute is precious, and being able to act fast could save you a lot of money in the long run.

  • Establish proper cloud storage security

    With cloud storage ubiquitous, ensuring the security of data stored in the cloud is imperative. Without proper security measures, sensitive information can be exposed and stolen. Take your time configuring your cloud storage for best security practices and if necessary, adopt additional security tools to protect your cloud storage.

  • Evaluate and monitor third-party risks

    Even if you can ensure complete security within your organization, remember that your data can be exposed via third parties such as your partner and vendors. Because supply chain attacks are on the rise, businesses need to evaluate their partnerships with third-parties security wise to minimize the risk of falling victim to a data breach.

What should you do if your data ends up in a data leak?

First, find out what kind of data was leaked. Account names, email addresses, and passwords often end up in data leaks. If your account was affected, change the password as soon as possible. If you used the same password anywhere else, you must change it on those other accounts. If you don't, you will be susceptible to a credential stuffing attack, and all your online accounts will be at risk.

If credit card and banking information were affected, you should contact your bank immediately and block your cards.

If your business experiences a data leak, swift action is critical. Make sure to contain the breach as soon as you discover it. Immediately start a detailed probe into what exactly happened and why it happened. Come forward to your customer base about the breach. Disclose all the relevant information: date of the leak, affected systems, affected users, and the type of the leak. Finally, make sure to level up the security infrastructure within the organization to lower the risk of future cyber incidents.

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