How to Check if Your Information Has Been Leaked in a Data Breach

Two years ago, a colleague of mine received a call from her bank. The bank said someone had tried to use her credit card. It turned out that her company's data had been leaked in a data breach that occurred several months earlier, but the company hadn't discovered it until the bank contacted them.

By that time, attackers had already had access to the information for several months. They had sold login credentials, tried to use credit cards, and even created fake accounts with the company's information. If the company had checked whether their information had leaked earlier, they could have discovered the problem much earlier and minimized the damage.

This is an all too common scenario. When company data leaks, it can take weeks or months before the organization discovers it. By that time, attackers may have already exploited the information in many ways. By regularly checking if your information has leaked, you can discover problems quickly and act immediately.

In this article, we'll explore how data breaches work, why it's important to discover them early, and what tools you can use to check if your information has leaked.

What Happens When Data Leaks?

When a data breach occurs, attackers often steal large amounts of data from companies. This can include email addresses, passwords, personal information, credit card information, and other sensitive data. This data is then often sold in various places, including the dark web, where other attackers can buy it.

The dark web is a part of the internet that's not indexed by regular search engines like Google or Bing. To access the dark web, you need special software, usually Tor, which encrypts your traffic and makes it hard to track. It's used by many different groups for various reasons, but part of it is used for illegal activities including selling stolen data.

The important thing to understand is that when your information appears in leaked databases, it often means a data breach has already occurred. It could be your own company that's been affected, or it could be a service you use that's been affected. Either way, it's important to discover it as soon as possible.

Why Is It Important to Discover Data Breaches Early?

There are several important reasons why it's so important to discover data breaches as early as possible. Let's look at some of the most important ones.

Minimize Damage

When your information leaks, attackers can use it in many different ways. They can try to log into your accounts, use your credit cards, or even create fake accounts in your name. The earlier you discover the leak, the faster you can take action to protect yourself.

In the example I mentioned earlier, the company could have discovered the data breach several months earlier if they had checked regularly. This would have given them the opportunity to change passwords, inform users, and take other actions before attackers could do so much damage.

Protect Your Reputation

When a data leak is discovered late, it can damage your company's reputation and trust. Customers and partners can lose trust if they find out their data has been exposed for several months without you knowing about it.

By quickly discovering and handling data leaks, you can minimize damage to your company's reputation. You can also show that you take security seriously by proactively checking if your information has leaked.

Prevent Future Attacks

When you discover that your information has leaked, you can also analyze how the leak occurred. This gives you the opportunity to improve your security measures and prevent similar incidents in the future.

Have I Been Pwned: A Free Tool to Check Data Breaches

One of the best tools for checking if your information has leaked is Have I Been Pwned. This is a free service created by security expert Troy Hunt that lets you check if your email address or phone number has appeared in known data breaches.

Have I Been Pwned collects information about data breaches from various sources and makes it searchable. When you enter your email address or phone number, the service searches through its database and tells you if your information has appeared in any known data breaches.

I use Have I Been Pwned regularly to check my own email addresses. A few months ago, I discovered that one of my email addresses had appeared in a data breach from a service I had used several years earlier. By discovering this, I could immediately change my password and activate two-factor authentication.

How to Use Have I Been Pwned

Using Have I Been Pwned is very simple. Go to the website haveibeenpwned.com and enter your email address in the search field. The service will then search through its database and tell you if your email address has appeared in any known data breaches.

If your email address has leaked, you'll get information about which data breach it was, when it occurred, and what type of data was exposed. This gives you all the information you need to take action.

Have I Been Pwned also offers a notification service where you can register your email address. If your email address appears in a new data breach in the future, you'll receive an email so you can take action immediately.

Limitations of Have I Been Pwned

It's important to understand that Have I Been Pwned only checks known data breaches. This means that if your information has leaked but the leak isn't known or documented, Have I Been Pwned won't find it.

The service also only checks email addresses and phone numbers, not other types of data like credit card information or personal details. That's why it's important to use Have I Been Pwned as part of a larger security strategy, not as the only measure.

Other Ways to Discover Data Breaches

Besides Have I Been Pwned, there are several other ways to discover if your information has leaked. Here are some of the most important ones.

Check Your Accounts Regularly

A simple but effective way to discover data breaches is to regularly check your accounts for suspicious activities. Look for logins from unknown locations, changes to your settings you didn't make, or unusual transactions.

Many services also offer features to see where and when your accounts have been used. By regularly reviewing this information, you can discover if someone unauthorized has gained access to your accounts.

Use Unique Passwords

One of the biggest problems with data breaches is that many people reuse passwords across multiple services. If your password leaks from one service, attackers can use it to access your other accounts.

By using unique passwords for each service, you can limit the damage if a data breach occurs. Even if your password leaks from one service, attackers can't use it to access your other accounts.

I recommend using a password manager to create and store unique passwords. This makes it much easier to manage many different passwords without having to remember them all.

Enable Two-Factor Authentication

Two-factor authentication is one of the best ways to protect your accounts, even if your passwords leak. When two-factor authentication is enabled, you need not only your password to log in, but also a code from your phone or another device.

This means that even if attackers get hold of your password, they can't log into your accounts without also having access to your phone. I strongly recommend enabling two-factor authentication on all important accounts, especially email, bank, and social media.

Stay Informed About Data Breaches

Many organizations inform their users when a data breach is discovered. By staying informed about data breaches, you can quickly take action if a service you use is affected.

You can also follow cybersecurity news to stay updated on major data breaches. Many security organizations and news sites regularly report on data breaches.

What to Do If Your Information Has Leaked

If you discover that your information has leaked, it's important to act quickly and systematically. Here are some steps you should follow.

1. Change Passwords Immediately

If your login credentials have leaked, change all related passwords immediately. This includes not only the account that was directly affected, but also all other accounts where you use the same or similar passwords.

I also recommend creating completely new, unique passwords for all accounts. Don't just use a small variation of your old password, but create completely new passwords that are strong and unique.

2. Enable Two-Factor Authentication

If you don't already have two-factor authentication enabled, do it now. This is especially important if your login credentials have leaked, as it gives you an extra layer of protection.

Many services offer two-factor authentication, and it's often very easy to enable. Go to your security settings and follow the instructions to enable two-factor authentication.

3. Check Your Accounts for Suspicious Activities

When your information has leaked, it's important to check all your accounts for suspicious activities. Look for logins from unknown locations, changes to your settings, or unusual transactions.

If you discover anything suspicious, contact the service immediately and follow their instructions to protect your account.

4. Inform Affected Parties

If company data has leaked, it's important to inform affected users so they can take action to protect themselves. This includes changing passwords, monitoring their accounts for suspicious activities, and in some cases contacting their banks or credit card companies.

It's important to be transparent but not panicked. Give users clear information about what has happened, what you're doing to solve the problem, and what they can do to protect themselves.

5. Investigate the Cause

When the immediate crisis is handled, it's important to investigate how the leak occurred. Was it a data breach? Was it a user who clicked on a phishing link? Was it a vulnerability in the system? By understanding the cause, you can prevent similar incidents in the future.

6. Improve Your Security

Use insights from the incident to improve your security. This can include updating security procedures, implementing new protections, or providing extra training to the team.

Practical Tips to Protect Yourself Against Data Breaches

Besides checking if your information has leaked, there are several things you can do to protect yourself against data breaches. Here are some practical tips.

Use Unique Passwords

As I mentioned earlier, it's important to use unique passwords for each service. This limits the damage if a data breach occurs. Use a password manager to make this easier.

Enable Two-Factor Authentication

Two-factor authentication is one of the best ways to protect your accounts. Enable it on all important accounts, especially email, bank, and social media.

Check Regularly

Check regularly if your information has leaked. I recommend using Have I Been Pwned at least once a month, or register for their notification service so you get warnings automatically.

Be Careful About What Information You Share

Be careful about what information you share online. The less information you share, the less can leak if a data breach occurs. Think about whether you really need to share all the information a service asks for.

Stay Informed

Stay informed about data breaches and cybersecurity. By staying updated, you can quickly take action if a service you use is affected.

Conclusion

Data breaches are a serious problem that's becoming increasingly common. By regularly checking if your information has leaked, you can discover problems quickly and take action to protect yourself.

Have I Been Pwned is an excellent tool for checking if your email addresses or phone numbers have appeared in known data breaches. It's free, easy to use, and can help you discover problems before attackers have time to exploit them.

But remember that Have I Been Pwned is only part of a larger security strategy. By using unique passwords, enabling two-factor authentication, and staying informed, you can better protect yourself against data breaches.

Start today by checking your email addresses on Have I Been Pwned. It only takes a few minutes, and it can help you discover problems before they become serious.