Incident Score: Analysis & Impact (CHAPOSTHERR-1769110042)
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Rankiteo Score Impact Analysis
Key Highlights From The Incident Analysis
- Timeline of RR Donnelley's Breach and lateral movement inside company's environment.
- Overview of affected data sets, including SSNs and PHI, and why they materially increase incident severity.
- How Rankiteo’s incident engine converts technical details into a normalized incident score.
- How this cyber incident impacts RR Donnelley Rankiteo cyber scoring and cyber rating.
- Rankiteo’s MITRE ATT&CK correlation analysis for this incident, with associated confidence level.
Full Incident Analysis Transcript
In this Rankiteo incident briefing, we review the RR Donnelley breach identified under incident ID CHAPOSTHERR-1769110042.
The analysis begins with a detailed overview of RR Donnelley's information like the linkedin page: https://www.linkedin.com/company/rr-donnelley, the number of followers: 254236, the industry type: Marketing Services and the number of employees: 40800 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 787 and after the incident was 738 with a difference of -49 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 RR Donnelley and their customers.
On 20 January 2026, Chatham Asset Management disclosed Data Breach issues under the banner "Chatham Asset Management Data Breach".
Chatham Asset Management, a New Jersey-based hedge fund specializing in alternative assets, confirmed a data breach after detecting unauthorized activity within its network on December 8, 2025.
The disruption is felt across the environment, and exposing Sensitive personally identifiable information (PII).
In response, teams activated the incident response plan, moved swiftly to contain the threat with measures like Secured systems, and stakeholders are being briefed through Regulatory disclosures and customer notifications.
The case underscores how Under investigation, with advisories going out to stakeholders covering Complimentary credit monitoring and identity restoration services through Cyberscout.
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.
MITRE ATT&CK® Correlation Analysis
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 Exploit Public-Facing Application (T1190) with moderate confidence (50%), supported by evidence indicating unauthorized activity within its network on December 8, 2025 and Valid Accounts (T1078) with moderate confidence (60%), supported by evidence indicating detecting unauthorized activity within its network. Under the Credential Access tactic, the analysis identified Unsecured Credentials (T1552) with moderate confidence (60%), supported by evidence indicating exposed sensitive PII such as Social Security numbers, driver’s license details and OS Credential Dumping (T1003) with moderate confidence (50%), supported by evidence indicating unauthorized activity within its network. Under the Collection tactic, the analysis identified Data from Local System (T1005) with moderate to high confidence (80%), supported by evidence indicating names, Social Security numbers, Driver’s license details compromised and Data from Information Repositories (T1213) with moderate to high confidence (70%), supported by evidence indicating high-net-worth clients sensitive PII exposed. Under the Exfiltration tactic, the analysis identified Exfiltration Over C2 Channel (T1041) with moderate to high confidence (80%), supported by evidence indicating threatened to publish stolen data on the dark web and Exfiltration Over Web Service (T1567) with moderate to high confidence (70%), supported by evidence indicating worldleaks claimed responsibility for the breach. Under the Impact tactic, the analysis identified Data Destruction (T1485) with lower confidence (40%), supported by evidence indicating threatened to publish stolen data on the dark web and Data Manipulation: Transmitted Data Manipulation (T1565.002) with moderate confidence (50%), supported by evidence indicating potential legal claims for those impacted. Under the Defense Evasion tactic, the analysis identified Indicator Removal (T1070) with moderate confidence (60%), supported by evidence indicating secured its systems and engaged third-party cybersecurity experts and Hide Artifacts (T1564) with moderate confidence (50%), supported by evidence indicating unauthorized activity detected, full scope under review. These correlations help security teams understand the attack chain and develop appropriate defensive measures based on the observed tactics and techniques.
Sources & References
- RR Donnelley Rankiteo Cyber Incident Details: https://www.rankiteo.com/company/rr-donnelley/incident/CHAPOSTHERR-1769110042
- RR Donnelley CyberSecurity Rating page: https://www.rankiteo.com/company/rr-donnelley
- RR Donnelley Rankiteo Cyber Incident Blog Article: https://blog.rankiteo.com/chapostherr-1769110042-chatham-asset-management-postmedia-mcclatchy-rr-donnelley-breach-june-2001/
- RR Donnelley CyberSecurity Score History: https://www.rankiteo.com/company/rr-donnelley/history
- RR Donnelley CyberSecurity Incident Source: https://www.claimdepot.com/investigations/chatham-asset-management-data-breach-2026
- Rankiteo A.I CyberSecurity Rating methodology: https://www.rankiteo.com/Images/rankiteo_algo.pdf
- Rankiteo TPRM Scoring methodology: https://static.rankiteo.com/model/rankiteo_tprm_methodology.pdf