Houghton Mifflin Harcourt Company
bd_3da1ab23695c5289 · schema v1 · pii pii-v1
Full breach record for Houghton Mifflin Harcourt Company →3 incidents on fileThreat-actor claim — not a regulatory filing
This row is a claim by the ransomware group Shinyhunters on its public extortion blog. It has not been validated by the victim or any regulator. Treat attribution and counts as the threat actor's assertion until a regulatory filing or victim disclosure corroborates them.
Source: Ransomware.live
Post text · scraped from the leak site
Your data was compromised in several of our campaigns throughout the past few months. We urge you to engage with us, it is in your best interests. This is a final warning to reach out by 12 May 2026 before we leak along with several annoying (digital) problems that'll come your way. Make the right decision, don't be the next headline. | Updated: 9 May 2026 | Warning: FINAL WARNING PAY OR LEAK
J jump to incidentP pin to compareR raw source
Incident timeline — mostly unverified
? — ?
Breach window unknown
May 9, 2026
Claim posted
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No filing yet · watching
Compliance clocks stay unassessable until a regulatory filing lands. Dashed segments fill in automatically when corroboration arrives.
Claim → filing
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Compliance clock
Not assessable
Evidence ladder
Attacker assertion only. Establishes: claim date, group, alleged victim.
Unlocks: incident narrative, operational impact. Still no compliance clock.
Unlocks: discovery date, data types, affected count, compliance clock.
Unlocks: materiality, stated response, full audit trail. Ceiling removed.
No regulatory filing corroborates this yet — it is the attacker's own assertion. Watch this entity to be notified the moment a filing corroborates or contradicts it.
Source ceiling
- actor name
- victim claim
- ransom/leak status
- discovery date
- materiality
- notification
- affected count
- confirmed data types
- compliance clock
The ✕ fields stay blank until a regulatory filing or victim disclosure lands.
shinyhunters
According to ransomware.live, ShinyHunters is a financially motivated data-theft and extortion group active since 2020, responsible for high-profile breaches including Ticketmaster (via Snowflake) and PowerSchool; by 2025 they launched a RaaS offering called "shinysp1d3r," and in August 2025 French authorities arrested four members.