Merck Breach Incident Score: Analysis & Impact (MER3502435111825)

In this Rankiteo incident briefing, we review the Merck breach identified under incident ID MER3502435111825.

The analysis begins with a detailed overview of Merck's information like the linkedin page: https://www.linkedin.com/company/merck, the number of followers: 2549401, the industry type: Pharmaceutical Manufacturing and the number of employees: 42297 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 834 and after the incident was 799 with a difference of -35 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 Merck and their customers.

On 17 November 2025, Merck Sharp & Dohme LLC disclosed Data Breach (Third-Party) issues under the banner "Data Breach at Merck via Third-Party Service Provider Graebel Companies".

On Sept.

The disruption is felt across the environment, and exposing Names, Dates of birth and Addresses, with nearly Unknown (potentially significant) records at risk.

In response, teams activated the incident response plan, moved swiftly to contain the threat with measures like Implemented by Graebel Companies, and began remediation that includes Enhanced security protocols by Graebel, and stakeholders are being briefed through Direct communication with affected individuals.

The case underscores how Ongoing (scope and full impact not yet determined), and recommending next steps like Monitor credit and financial accounts for suspicious activity and Enroll in complimentary credit monitoring and identity theft protection services (provided by TransUnion for 24 months), with advisories going out to stakeholders covering Direct notifications sent to affected individuals.

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 Trusted Relationship (T1199) with moderate to high confidence (85%), supported by evidence indicating third-party service provider, Graebel Companies, suffered a data breach exposing sensitive PII. Under the Collection tactic, the analysis identified Data from Local System (T1005) with high confidence (90%), supported by evidence indicating compromised data includes names, SSNs, financial account details stored by Graebel. Under the Exfiltration tactic, the analysis identified Exfiltration Over Alternative Protocol: Exfiltration Over Unencrypted/Obfuscated Non-C2 Protocol (T1048.003) with moderate to high confidence (75%), supported by evidence indicating data breach exposing sensitive personal and financial information (method unspecified, but exfiltration implied). Under the Impact tactic, the analysis identified Identity Theft (T1659) with high confidence (95%), supported by evidence indicating heightening risks of identity theft and fraud due to exposed SSNs/financial data. These correlations help security teams understand the attack chain and develop appropriate defensive measures based on the observed tactics and techniques.