Coupang Breach Incident Score: Analysis & Impact (COU1764467849)

In this Rankiteo incident briefing, we review the Coupang breach identified under incident ID COU1764467849.

The analysis begins with a detailed overview of Coupang's information like the linkedin page: https://www.linkedin.com/company/coupang, the number of followers: 226701, the industry type: Software Development and the number of employees: 7994 employees

After the initial compromise, the video explains how Rankiteo's incident engine converts technical details into a normalized incident score. The incident score before the incident was 560 and after the incident was 497 with a difference of -63 which is could be a good indicator of the severity and impact of the incident.

In the next step of the video, we will analyze in more details the incident and the impact it had on Coupang and their customers.

On 29 November 2025, Coupang disclosed Data Breach and Unauthorized Access issues under the banner "Massive Data Breach at Coupang Affecting 33.7 Million Customers".

A massive data breach at e-commerce giant Coupang compromised personal information of 33.7 million customers, nearly its entire user base.

The disruption is felt across the environment, affecting Delivery-Related Databases and Overseas Servers, and exposing Names, Phone Numbers and Email Addresses, with nearly 33.7 million records at risk.

In response, teams activated the incident response plan, and stakeholders are being briefed through Public disclosure on November 29; initial underreporting (4,500 accounts) corrected later.

The case underscores how Ongoing (police investigating breach origins and scope).

Finally, we try to match the incident with the MITRE ATT&CK framework to see if there is any correlation between the incident and the MITRE ATT&CK framework.

The MITRE ATT&CK framework is a knowledge base of techniques and sub-techniques that are used to describe the tactics and procedures of cyber adversaries. It is a powerful tool for understanding the threat landscape and for developing effective defense strategies.

Rankiteo's analysis has identified several MITRE ATT&CK tactics and techniques associated with this incident, each with varying levels of confidence based on available evidence. Under the Initial Access tactic, the analysis identified External Remote Services (T1133) with moderate to high confidence (85%), supported by evidence indicating unauthorized access to delivery-related personal information... through overseas servers since June 24 and Valid Accounts (T1078) with moderate to high confidence (70%), supported by evidence indicating compromised Overseas Servers (potential misuse of legitimate remote access credentials). Under the Persistence tactic, the analysis identified Account Manipulation (T1098) with moderate confidence (65%), supported by evidence indicating breach undetected for ~5 months suggests potential backdoor or persistent access via overseas servers. Under the Exfiltration tactic, the analysis identified Exfiltration Over Alternative Protocol (T1048) with high confidence (90%), supported by evidence indicating data exfiltration such as Yes (via overseas servers), 33.7 million records exposed and Automated Exfiltration (T1020) with moderate to high confidence (80%), supported by evidence indicating large-scale PII exfiltration (33.7M records) suggests automated processes over 5 months. Under the Defense Evasion tactic, the analysis identified Indicator Removal: File Deletion (T1070.004) with moderate to high confidence (70%), supported by evidence indicating breach remained undetected for 5 months (implies log tampering or evidence removal) and Impair Defenses: Disable or Modify Tools (T1562.001) with moderate confidence (60%), supported by evidence indicating long-term undetected access suggests potential disabling of monitoring/alerting on overseas servers. Under the Collection tactic, the analysis identified Data from Local System (T1005) with high confidence (95%), supported by evidence indicating delivery-related personal information (PII) collected from customer databases. Under the Impact tactic, the analysis identified Data from Cloud Storage Object (T1598) with moderate to high confidence (85%), supported by evidence indicating delivery-Related Databases (likely cloud-hosted) accessed for PII exfiltration. These correlations help security teams understand the attack chain and develop appropriate defensive measures based on the observed tactics and techniques.