Imagine that the largest e-commerce platform in your country—the “Amazon of South Korea”—discovers that nearly its entire user base has been leaking sensitive information for five months. That’s exactly what just happened to Coupang, one of Asia’s biggest e-commerce and logistics platforms, which has confirmed a security breach affecting 34 million customers.
If you manage a digital business or handle sensitive data, this case offers key lessons about late detection, prolonged exposure, and the danger of assuming your vendors are “already secured.” At TecnetOne, we often see the same pattern repeat: large companies with advanced technology but weak or flawed internal controls.
Coupang confirmed that the breach began on June 24, 2025, via servers located overseas. What’s most concerning is not just the scale of the attack, but the fact that it went unnoticed for over five months.
The company eventually blocked access, reinforced internal monitoring, and hired external experts to investigate—but the response came too late.
The first sign of trouble emerged on November 18, when the security team noticed suspicious activity in 4,500 accounts. Initially thought to be a minor incident, further investigation revealed the true extent: 33.7 million accounts affected in South Korea alone.
The company stated that no financial data or passwords were compromised, but highly sensitive personal information was exposed—ideal for fraud, social engineering, and identity theft. Exposed data included:
Even without banking details, this kind of data is enough to launch more sophisticated attacks. Criminals can build complete profiles, craft personalized phishing attempts, commit refund or delivery scams, and exploit the trust between users and the platform.
At TecnetOne, we see time and again that vulnerabilities are often found in the "non-critical" data companies tend to overlook.
Learn more: Google Hit by Data Breach Following Salesforce Attacks
Coupang isn’t just any company. Consider these numbers:
This means more people were impacted than their active customer count suggests—due to old accounts, inactive profiles, or occasional buyers. Massive breaches like this don’t just affect current users, but also those who left their data on the platform years ago.
While the investigation is ongoing, Korean authorities have identified a suspect:
Although not yet confirmed, all signs point to an insider threat—a common and dangerous attack vector. At TecnetOne, we stress this constantly when discussing access governance and Zero Trust: when someone who knows the infrastructure and its weak points decides to exploit that knowledge, the damage is deeper and harder to detect.
The breach prompted immediate action from the South Korean government. ICT Minister Bae Kyung-hoon called an emergency meeting and announced increased vigilance over the next three months to prevent secondary damage.
This includes:
South Korea is among the most digitally connected countries in the world, so incidents like this can have significant social impact.
This is not Coupang’s first breach:
This pattern suggests deeper issues in their security architecture, internal processes, and access reviews. When breaches repeat, it often indicates:
For any company managing large datasets, this is a clear warning: security isn’t a one-time project. It’s a disciplined, continuous process.
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This incident proves you don’t need to lose your password to become a victim. With the leaked data, criminals can:
Many criminals wait weeks or even months before using leaked data—precisely to strike when vigilance fades.
At TecnetOne, we see the same cycle too often: businesses digitize everything—except their security.
Key lessons from Coupang’s breach:
The Coupang breach shows what happens when a tech giant leaves a door open for months: millions exposed, attackers enriched, and risks that multiply even after the breach is contained.
Security today is not a luxury—it’s a continuous responsibility.
And if a company as big as Coupang can fall like this, any business—including yours—should rethink its defense strategy before the same happens.