Group Health Cooperative of South Central Wisconsin Breach Incident Score: Analysis & Impact (GRO1092510111225)

In this Rankiteo incident briefing, we review the Group Health Cooperative of South Central Wisconsin breach identified under incident ID GRO1092510111225.

The analysis begins with a detailed overview of Group Health Cooperative of South Central Wisconsin's information like the linkedin page: https://www.linkedin.com/company/group-health-cooperative-of-south-central-wisconsin, the number of followers: 3051, the industry type: Hospitals and Health Care and the number of employees: 490 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 764 and after the incident was 614 with a difference of -150 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 Group Health Cooperative of South Central Wisconsin and their customers.

On 24 January 2024, Group Health Cooperative of South Central Wisconsin (GHCSCW) disclosed Data Breach issues under the banner "GHC-SCW $3.5M Data Breach Class Action Settlement".

Group Health Cooperative of South Central Wisconsin (GHCSCW) agreed to pay $3.50 million to resolve a class action lawsuit alleging failure to prevent a data breach on or about Jan.

The disruption is felt across the environment, affecting Network systems, and exposing Personally Identifiable Information (PII) and Protected Health Information (PHI), with nearly 533,809 records at risk, plus an estimated financial loss of $3,500,000 (settlement fund).

In response, while recovery efforts such as $3.5M settlement fund for affected members and Three years of CyEx Medical monitoring services (credit monitoring, dark web scanning, identity theft insurance) continue, and stakeholders are being briefed through Notice sent to affected individuals, Official settlement website for claims and Mail-in claim forms.

The case underscores how Settled (final approval hearing on 2026-02-04), with advisories going out to stakeholders covering Notice to affected members and Settlement website and claim forms.

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 Valid Accounts (T1078) with moderate to high confidence (70%), supported by evidence indicating high-value targets such as Personal and health data of members implies abuse of valid access to systems. and Exploit Public-Facing Application (T1190) with moderate confidence (60%), supported by evidence indicating vulnerabilities in healthcare data protection suggests potential exploitation of public-facing apps.. Under the Collection tactic, the analysis identified Data from Local System (T1005) with high confidence (95%), supported by evidence indicating personally Identifiable Information (PII), Protected Health Information (PHI) compromised (533,809 records).. Under the Exfiltration tactic, the analysis identified Exfiltration Over Alternative Protocol (T1048) with high confidence (90%), supported by evidence indicating data exfiltration such as Likely (dark web scanning included in settlement services). and Automated Exfiltration (T1020) with moderate to high confidence (80%), supported by evidence indicating 533,809 records exposed suggests automated collection/exfiltration at scale.. Under the Impact tactic, the analysis identified Data Encrypted for Impact (T1486) with lower confidence (30%), supported by evidence indicating no ransomware details provided, but data breach led to identity theft risks., Resource Hijacking (T1496) with lower confidence (40%), supported by evidence indicating settlement includes dark web scanning, implying potential misuse of exfiltrated data., and Data Theft for Extortion (T1659) with moderate to high confidence (85%), supported by evidence indicating $3.5M settlement for data breach with identity theft risks and dark web monitoring.. Under the Defense Evasion tactic, the analysis identified Indicator Removal: File Deletion (T1070.004) with moderate confidence (50%), supported by evidence indicating no forensic details provided, but lack of detection until after breach suggests evasion.. Under the Credential Access tactic, the analysis identified Unsecured Credentials: Credentials In Files (T1552.001) with moderate confidence (60%), supported by evidence indicating allegations of negligence and failure to implement adequate security measures.. These correlations help security teams understand the attack chain and develop appropriate defensive measures based on the observed tactics and techniques.