Most organizations invest in tools to prevent data leaks. However, a portion of their sensitive information is likely already exposed somewhere on the internet, without their knowledge. Understanding enterprise data leaks means accepting a fundamental shift in perspective: the question is not only “how to block,” but “how to find out what has already slipped through.”
According to the CNIL 2024 annual report (published in April 2025), 5,629 personal data breaches were reported in France, a 20% increase compared to 2023. The number of breaches affecting more than one million people doubled in a single year.
What Is an Enterprise Data Leak?
An enterprise data leak is any unauthorized disclosure of sensitive information belonging to the organization or its clients. It can result from human error, a misconfiguration, or a malicious action, whether internal or external.
Unlike a declared cyberattack, it often goes unnoticed for weeks or even months. Exposed data can include login credentials, contracts, financial records, customer personal data, or trade secrets. According to IBM, the average cost of a data breach in France reached 3.59 million euros in 2025 (IBM Cost of a Data Breach 2025).
Key takeaway: A data leak does not always trigger a security alert. In most cases, it is discovered by a third party, such as a journalist, a client, or a security researcher, rather than by the affected organization itself.
Why Classic DLP Tools Are No Longer Enough
Data Loss Prevention (DLP) solutions are designed to monitor and block data transfers inside the organization’s perimeter: misdirected emails, USB copy operations, unauthorized shares on cloud platforms. They provide useful protection, but they carry a fundamental blind spot.
A DLP tool does not monitor what happens outside your network. It does not detect employee credentials being sold on a cybercriminal forum. It does not flag that a former contractor still holds active access to your environment. Nor does it identify that a developer pushed a configuration file containing API keys to a public GitHub repository.
These blind spots are precisely where attackers look first. Consequently, limiting your strategy to internal prevention is like locking your front door while leaving the back window open.
The Three Leak Sources Your Organization Is Not Monitoring
Several external exposure vectors remain systematically under-monitored in organizations, even those that have deployed DLP tools.
The Dark Web and Cybercriminal Forums
Thousands of French company credentials are listed for sale every week on specialized marketplaces or shared freely on forums. These datasets come from earlier breaches, sometimes occurring at partners or suppliers rather than directly within your information system. Without active monitoring of these sources, you will never know your credentials are compromised before they are used against you.
Public Repositories and Misconfigured Cloud Services
Misconfigurations are among the most frequent causes of unintentional data exposure. A publicly accessible S3 bucket, a GitHub repository containing environment variables, a document shared with “everyone” on a collaborative platform: each of these situations exposes real data without triggering any internal alert. ANSSI identifies these misconfigurations as one of the primary sources of leaks in its reference guide on protection against data leaks, available at messervices.cyber.gouv.fr.
Data Exposed Through the Supply Chain
Your data does not stay within your perimeter. It flows to your suppliers, subcontractors, software vendors, and commercial partners. A breach at one of them potentially exposes yours as well. Furthermore, access granted to third parties is not always revoked when a collaboration ends. These orphaned access points represent a direct and often overlooked attack surface.
How Does External Data Leak Detection Work?
External data leak detection is based on an approach fundamentally different from DLP. Rather than filtering outbound flows, it continuously monitors open and closed sources where your organization’s data might appear.
This approach relies on two complementary disciplines. EASM (External Attack Surface Management) is a method for continuously mapping and monitoring an organization’s external exposure: exposed assets, accessible services, vulnerabilities visible from the internet. It reduces the attack surface before it is exploited. Data leak detection is the active monitoring of sources where organizational data may have been disclosed: dark web, paste sites, public repositories, specialized forums, compromised databases.
Together, these two disciplines answer a question DLP tools never ask: what can your attackers already see about you?
| Criterion | Internal DLP | EASM + Data leak detection |
|---|---|---|
| Monitored perimeter | Internal network and endpoints | External sources, dark web, public repositories |
| Detection nature | Preventive (blocks before the leak) | Detective (identifies what has already leaked) |
| Third-party visibility | Limited | Extended to the supply chain |
| Detection timing | Real-time on internal flows | Continuous across open and closed sources |
| Main blind spot | Data already outside the perimeter | Unmonitored internal flows |
NIS2 and DORA: A Monitoring Obligation That Extends Beyond Your IT Systems
The NIS2 directive, currently being transposed into French law following its adoption by the Senate in March 2025, requires essential and important entities to continuously monitor their information systems and maintain incident detection capabilities. It also mandates reporting to ANSSI within 24 hours of a significant incident, along with formal management of third-party supplier risks. These obligations make external detection necessary, not optional.
The DORA regulation (Digital Operational Resilience Act), applicable since January 2025 to financial entities, requires an ICT contracts register, operational resilience testing, and formalized management of third-party risks. Monitoring the external attack surface directly addresses these requirements by identifying exposures from the supply chain before they are exploited.
For a mid-sized organization subject to NIS2 or DORA, outsourcing data leak detection to a French provider without offshoring is not only an operational advantage. It is a direct response to regulatory requirements around data sovereignty, incident notification, and third-party risk management.
What NIS2 says: Article 21 of the directive requires continuous monitoring measures and incident detection capabilities. An organization unaware of what circulates on external sources cannot demonstrate detection capabilities compliant with NIS2 requirements.
What Stroople Monitors on Your Behalf
Stroople’s Threat Exposure Management service combines EASM and data leak detection in a continuous monitoring program. In practice, Stroople tracks your external exposure across open and closed sources: compromised credentials, data surfacing on the dark web, misconfigured assets, orphaned access points at your suppliers. Each alert is qualified by analysts, then delivered with a clear remediation plan.
External Attack Surface Management
See your exposure before attackers do. Know what's already compromised.
of successful breaches start from publicly exposed assets.