How to Prevent Data Leaks

‍Data leak prevention is a cybersecurity practice that involves implementing secure data practices to reduce accidental exposure. Effective data leak prevention plays a crucial role in a comprehensive data loss prevention strategy (DLP strategy).

Data leaks are an easy attack vector for cybercriminals. Exposed data, such as leaked credentials, allows unauthorized access to an organization's systems. This direct access enables hackers to carry out a range of cyber attacks with less effort, such as:

• Ransomware and other types of malware injections
• Social engineering, including phishing
• Data exfiltration/data theft

What is a data leak?

A data leak is an overlooked exposure of sensitive data, either electronically or physically. Data leaks could occur internally or via physical devices such as external hard drives or laptops. If a cybercriminal locates a data leak, they can use the information to arm themselves for a data breach attack.

When sensitive data is stolen from either a data breach or a ransomware attack and published on the dark web, these events are also classified as data leaks.

The difference between data leaks and data breaches

A data leak is the accidental exposure of sensitive information. These events are not initiated by an external impetus. They're caused by vulnerabilities in the security controls protecting confidential data. Data leaks can also be caused by cybercriminals publishing stolen data on their official dark web noticeboards, also known as ransomware blogs.

A data breach, on the other hand, is the outcome of a planned cyberattack. These events are initiated by an external impetus. Before sensitive data can be detected and exfiltrated, cybercriminals must overcome a series of data security measures securing the cyber kill chain.

Learn how to prevent data breaches >

Data loss is another term commonly associated with data leaks. Data loss is the irreversible loss of sensitive data, either by accidental deletion or theft.

These events can be mitigated with Data Loss Prevention (DLP) strategies that prevent data transfer beyond specified boundaries. However, a DLP strategy alone will not prevent data leaks; its focus is too narrow.

Data leak prevention efforts need to consider all of the processes that have a direct and indirect impact on sensitive data protection. This effort even stretches as far back as the coding practices that develop a solution.

Learn more about the differences between data leaks, data breaches, and data loss >

What is data leakage protection?

While related to DLP, data leakage protection refers specifically to the measures and technologies used to detect, monitor, and prevent sensitive data from being exposed or transferred outside an organization. This approach is proactive and highly focused, aiming to address the vulnerabilities and accidental exposures that often precede a major data breach.

Data leaks are a common and easy attack vector for cybercriminals. Exposed data, such as leaked credentials, allows unauthorized access to an organization's systems.

For instance, a proactive data leakage protection tool like UpGuard doesn't wait for a system to be breached; it searches the external environment for existing leaks. UpGuard can help prevent an attack by:

• Alerting on exposed credentials found on the dark web, hacker forums, and ransomware blogs, allowing you to invalidate them before they are used to access your systems.
• Identifying leaked vendor information that could be used in a supply chain attack gives you visibility into third-party risks that directly impact your security posture.

A data leak is an overlooked exposure of sensitive data, whether it occurs electronically or physically. These events are not initiated by an external impetus; they're caused by vulnerabilities in the security controls protecting confidential data. A data breach, on the other hand, is the outcome of a planned cyber attack.

Essential data leak prevention tools

A successful data leakage protection strategy requires the right combination of tools that provide both internal monitoring and external visibility. These technologies help you detect and close security gaps before they can be exploited by an attacker.

Here are the core technologies that enable an effective data leak prevention strategy:

• Data Loss Prevention (DLP) software: These internal tools monitor and control data in transit and at rest within your network, typically by classifying sensitive information and enforcing policies to prevent unauthorized movement.
• Encryption and secure file transfer protocols: Robust encryption should be used to protect data when it must be stored or transferred outside of specified boundaries, even if a leak occurs.
• Cloud security monitoring: These tools continuously check for critical misconfigurations and vulnerabilities in cloud environments, such as exposed S3 buckets, which are a common cause of data leaks.
• Dark web scanning tools: These are crucial for actively searching external sources, such as hacker forums and ransomware blogs, for leaked or stolen internal and third-party data that cybercriminals intend to exploit.
• UpGuard’s risk assessment and alerting tools: These tools identify and continuously monitor your external attack surface, as well as that of your vendors’ networks, to detect security exposures before attackers do.

‍

Why is data leakage prevention important?

Leaked data is a treasured find for a cybercriminal. These events significantly reduce the effort of cybercrime by removing all of the laborious stages preceding data compromised in the cyber kill chain.

Because they make life so much easier for cybercriminals, data leak finds are becoming a primary focus in the world of cybercrime. Meeting this performance metric is relatively easy, given the growing prevalence of data leaks.

A 2021 UpGuard study revealed that half of analyzed Fortune 500 companies were leaking data useful for cybercriminal reconnaissance in their public documents.

Also, in 2021, UpGuard researchers discovered that at least 47 organizations were unknowingly leaking data through a misconfiguration in Microsoft's PowerApp solutions - an oversight resulting in the exposure of tens of millions of private records.

Many organizations unknowingly leak sensitive data sets, potentially exposing trade secrets, Personal Identifiable Information (PII), and even credit card data.

The normalization of data breach prevention efforts will likely positively impact all other cybersecurity sectors. The degree of sensitive data exposure is proportional to the success of data breaches and phishing attacks. Both events could, therefore, be reduced if data leaks are remediated before cybercriminals discover them.

What is data leakage protection?

Data leak prevention is a cybersecurity practice that involves implementing secure data practices to reduce accidental exposure. Effective data leak prevention plays a crucial role in a comprehensive DLP strategy.

While related to DLP, data leakage protection refers specifically to the measures and technologies used to detect, monitor, and prevent sensitive data from being exposed or transferred outside an organization. This approach is proactive and highly focused, aiming to address the vulnerabilities and accidental exposures that often precede a major data breach.

Data leaks are a common and easy attack vector for cybercriminals. Exposed data, such as leaked credentials, allows unauthorized access to an organization's systems.

For instance, a proactive data leakage protection tool like UpGuard doesn't wait for a system to be breached; it searches the external environment for existing leaks. UpGuard can help prevent an attack by:

• Alerting on exposed credentials found on the dark web, hacker forums, and ransomware blogs, allowing you to invalidate them before they are used to access your systems.
• Identifying leaked vendor information that could be used in a supply chain attack gives you visibility into third-party risks that directly impact your security posture.

A data leak is an overlooked exposure of sensitive data, whether it occurs electronically or physically. These events are not initiated by an external impetus; they're caused by vulnerabilities in the security controls protecting confidential data. A data breach, on the other hand, is the outcome of a planned cyber attack.

What causes data leaks?

Data leaks occur when sensitive data is accidentally exposed publicly, either physically or digitally. Common causes of data leaks include:

• Misconfigured software settings
• Social engineering
• Recycled or weak passwords
• Physical theft/loss of sensitive devices
• Software vulnerabilities
• Insider threats

Learn more about the common causes of data leaks >

Examples of data leaks

The holy grail of sensitive information exposure is Personally Identifiable Information (PII), including names, contact information, financial details, and other personal data. Other less potent forms of data leaks can be used for reconnaissance missions to uncover internal secrets.

There are four major categories of data leaks - customer information, company information, trade secrets, and analytics.

1. Customer information

Some of the biggest data breaches included customer data leaks that involved Personal Identifiable information. Customer data is unique to each company. Customer confidential information could include any of the following:

• Customer names
• Addresses
• Phone number
• Email addresses
• Usernames
• Passwords
• Social Security numbers
• Payments histories
• Product browsing habits
• Credit Card numbers

2. Company information

Leaked company information exposes sensitive internal activity. Such data leaks tend to be in the crosshairs of unscrupulous businesses pursuing the marketing plans of their competitors.

Company data leaks could include the following:

• Internal communications
• Performance metrics
• Marketing strategies

3. Trade secrets

This is the most dangerous form of data leak to a business. Intellectual property theft destroys a business's growth potential, running it to the ground.

Trade secret leakage could include the following types of data:

• Upcoming product plans
• Software coding
• Proprietary technology information

4. Analytics

Large data sets feed analytics dashboards, and cybercriminals are drawn to any sizable pool of data. Analytics software is, therefore, an attack vector that needs to be monitored.

Analytics data leaks could include the following:

• Customer behavior data
• Psychographic data
• Modeled data

Common hosts of data leak dumps

There has been enough data breach intelligence analyzed to paint a picture of common cybercriminal behavior. Thanks to this data, we can now deploy security controls along each stage of the cyberattack lifecycle.

Data breach post-mortem analysis has also unveiled common cybercriminal behavior beyond a successful breach. After exploiting leaked data, the next stop for cybercriminals is usually dark web forums, where they either put it up for sale or publish it freely.

Such forums need to be continuously monitored in a data leak detection strategy.

Data leaks could still offer helpful reconnaissance information while in the process of being sold. Dark web marketplace listings often include a sample of compromised data to prove the authenticity of the event.

By cross-referencing the sample information against your third-party vendor list and a database of known breaches, such as Have I Been Pwnd, the source of the leak could be identified.

The following popular dark web forums should be monitored for data leaks:

• Nulled
• Dread
• Crackingking
• Cryptbb
• Raidforums
• Freehacks
• Hacktown
• Xss.is
• exploit.in
• evilzone.org
• 4chan

Learn how to reduce data leak false positives >

Ransomware blog data leaks

Another common cause of data leaks is data dumps from ransomware attacks. Hackers publish data stolen from ransomware attacks on dark websites known as ransomware blogs (or ransomware sites). Ransomware blogs are like noticeboards for specific ransomware groups, hosting official updates as well as data dumps.

A data leak prevention strategy must accommodate for these types of leaks by implementing security measures beyond the final phase of the ransomware attack lifecycle - after the data dump phase (phase 8).

Learn how to reduce the impact of ransomware attacks >

A ransomware data leak security tool monitors popular ransomware blogs for critical data and internal confidential information (like employee credentials leaks). If ransomware leaks are left unaddressed, cybercriminals could use them to instantly gain access to a private network without the usual social engineering processes that preclude unauthorized access attempts.

Armed with internal credentials from a ransomware blog, cybercriminals could circumvent the perimeter penetration phases - the most difficult stages of a ransomware attack - leaving just the challenge of escalating permissions before a breach is achieved.

The resulting compressed ransomware lifecycle, which makes data breaches easier and faster to accomplish, highlights the critical need for ransomware leak security measures in security policies.

Request a free demo of UpGuard's ransomware data leak solution >

Addressing the source of data leaks

The most effective and sustainable cybersecurity initiatives are those that assume a proactive approach to protection.

Data leak monitoring efforts are reduced if the vulnerabilities facilitating data leaks are addressed.

This is most efficiently achieved with an attack surface monitoring solution. Such a solution will discover the security vulnerabilities inside your ecosystem and those throughout your third-party vendor network.

Monitoring the third-party attack surface is crucial since over half of data breach events result from compromised third-party vendors.

Since most breaches stem from compromised third parties, it's safe to assume that your vendors aren't addressing data leaks in their cybersecurity practices.

Because of this, the scope of a data leak detection strategy should also extend to the third-party landscape.

Since data leaks commonly preceded data breaches, this effort will reduce third-party breaches and supply chain attacks and, therefore, most data breach events.

8 tips to protect your business from data leaks in 2025

The following data security practices could prevent data leaks and minimize the chances of data breaches.

8 tips to protect your business from data leaks

The following data security practices could prevent data leaks and minimize the chances of data breaches.

1. Perform regular risk assessments

Since over half of data breach events result from compromised third-party vendors, monitoring the third-party attack surface is crucial.

• Monitor vendor security posture: Vendor risk assessments are a common method of identifying third-party security risks and ensuring compliance with regulatory standards, such as HIPAA, PCI-DSS, or GDPR.
• Use security scoring for efficiency: Security scoring is a highly efficient way of evaluating a vendor's susceptibility to data breaches. The UpGuard platform assigns all vendors a security score based on an analysis of 70+ critical vectors.

‍

Learn more about UpGuard's security rating feature >

2. Limit access control

Your confidential data may currently be accessible to users who don't require it.

• Enforce least privilege: Evaluate all permissions to ensure access isn't being granted to unauthorized parties.
• Segment data: Categorize all critical data into different levels of sensitivity to control access to different pools of data. This privileged access assignment process may also identify malicious insiders.
  

3. Identify and classify all sensitive data

Before DLP policies can be initiated, businesses need to identify all of the sensitive data that needs to be secured.

• Discovery and classification: This data then needs to be correctly classified in line with strict security policies. Classification categories could include Protected Health Information (PHI), financial data, and other sensitive data forms.
• Tailor defenses: Correct classification allows a business to tailor the most efficient data leak prevention defenses for each data category.

4. Secure all endpoints and educate employees

With most organizations now adopting remote working models, endpoints have become more challenging to secure.

• Extend endpoint coverage: Extend your coverage to cloud-based endpoint security, covering all remote access points, including IoT devices, desktops, and mobile devices.
• Train against social engineering: Staff are often tricked into introducing malware to bypass security defenses. Organizations need to train their staff to recognize the trickery of cyberattackers, particularly email phishing and social engineering attacks.

5. Implement a layered DLP strategy

Data loss prevention (DLP) is an overarching data protection strategy that should include data leak prevention as a core component. An effective DLP system combines processes and technology.

• Apply internal controls: DLP components include securing data in motion, securing endpoints, securing data at rest, and securing data in use (monitoring unauthorized user behavior).
• Add external leak detection: If data leak prevention strategies fail, fast remediation is crucial to preventing a data breach. Effective data leak detection tools (like UpGuard’s threat monitoring) can scan the open and deep web for data exposures, including S3 buckets and GitHub repositories, enabling faster removal of potential breach vectors.

6. Encrypt all data

Cybercriminals may struggle to exploit data leaks if the data is encrypted.

• Use encryption as a layer: Encryption (Symmetric-Key or Public-Key) should not be the sole data leak prevention tactic, but rather used in conjunction with other methods.

Learn how tech companies can detect data leaks >

7. Proactively monitor external sources

Data breach post-mortem analysis has unveiled common cybercriminal behavior: after exploiting leaked data, the next stop is usually dark web forums, where they either put it up for sale or publish it freely.

• Scan ransomware blogs: Another common cause of data leaks is the publication of data dumps from ransomware attacks on dark websites known as ransomware blogs.
• Use threat monitoring: A ransomware data leak security tool monitors popular ransomware blogs for critical data and internal confidential information. UpGuard’s threat monitoring helps organizations identify and strengthen security vulnerabilities to prevent reconnaissance campaigns.

8. Patch and address software vulnerabilities

The most effective and sustainable cybersecurity initiatives are those that assume a proactive approach to protection.

• Use attack surface monitoring: Data leak monitoring efforts are reduced if the vulnerabilities facilitating data leaks are addressed. This is most efficiently achieved with an attack surface monitoring solution.
• Cover vendors: Such a solution will discover the security vulnerabilities inside your ecosystem and those throughout your third-party vendor network.

The UpGuard platform assigns all vendors a security score based on an analysis of 70+ critical vectors.

Key takeaways

Preventing accidental data exposure is a multi-layered effort that focuses on both your internal environment and your external attack surface. To recap the most essential actions and strategies:

• Data leaks are preventable with the right visibility and tools—the goal is to find the exposed data before cybercriminals do.
• DLP software and real-time external alerting (such as dark web scanning) play a critical role in detecting and remediating exposures across all stages of the attack lifecycle.
• UpGuard supports proactive detection and third-party monitoring to provide a comprehensive, external view of your attack surface and supply chain risk.
• Regular assessments and continuous monitoring of both your own environment and your vendors' security postures are crucial to identifying and closing security gaps before they are exploited.

‍

‍