Summary
On October 3, 2025, the notorious ransomware group ShinyHunters launched an attack against
HMH (hmhco.com), a prominent U.S.-based educational publishing company. The threat actor claims to hold sensitive information and has threatened to release it unless negotiations are initiated.
Incident Report
| Field | Details |
|---|---|
| Target | HMH |
| Domain | hmhco.com |
| Country | USA |
| Attacking Group | ShinyHunters |
| Date Reported | October 3, 2025 |
| Threat Actor Statement | “The full leak will be published soon, unless a company representative contacts us via the channels provided.” |
About HMH
HMH, or Houghton Mifflin Harcourt, is a long-established publishing company renowned for its educational content. Serving schools in over 150 countries, HMH provides instructional technology, assessments, and learning materials. The company also publishes well-known trade and reference works, alongside children’s books, with a mission to foster a lifelong love of learning.
About ShinyHunters
ShinyHunters is a cybercriminal group known for targeting high-profile organizations and leaking sensitive data. They have been linked to numerous data breaches, focusing primarily on extracting ransoms in exchange for not releasing compromised data.
Proactive Response to Ransomware Threats
Organizations must take proactive measures to guard against ransomware threats. Dark web monitoring is crucial for identifying potential data breaches early. Utilizing tools like email breach checkers can help companies stay alert to unauthorized access. Visit mspdarkintel.com/domain-breach-scan to keep an eye on your company’s data security and mitigate potential risks.
Recommendations
- Monitor your domains and email addresses for exposure using reputable threat intelligence tools.
- Conduct a full compromise assessment and incident response drill internally.
- Verify backups and ensure they are offline and ransomware-resistant.
- Educate staff on phishing, social engineering, and lateral movement techniques used by groups like Qilin.
- Engage with cyber forensics and legal counsel before initiating contact with threat actors.
Check Your Exposure
Wondering if your organization or employees are impacted by recent breach activity?
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Check domain-wide breach exposure:
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Check if an email was breached:
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Disclaimer
The MSPDarkIntel team does not engage in the exfiltration, downloading, taking, hosting, viewing, reposting, or disclosure of any stolen information.
All breach data reported here is sourced from publicly available threat intelligence feeds for awareness and early-warning purposes only.
Our goal is to inform organizations of emerging threats so they can take timely defensive action.
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