Cierant Corporation Data Breach Lawsuit Investigation
Did you receive a notice from Cierant or Blue Cross Blue Shield of Massachusetts? A ransomware gang claims it leaked your personal and medical data online. Act now—learn what was exposed, the free protections available, and whether you can pursue compensation.
What Happened?
On December 10, 2024, Cierant Corporation—an outbound marketing and data-processing vendor based in Danbury, Connecticut—detected unauthorized activity on its network. An internal forensic review determined that threat actors exploited a known vulnerability in the Cleo VLTrader file-transfer platform, allowing them to infiltrate and exfiltrate files containing health-plan member data.
The notorious CL0P ransomware group later claimed responsibility and posted stolen files on a Tor-based leak site. Cierant completed its investigation and, by July 3, 2025, began mailing individual notification letters. The breach was formally reported to the California Attorney General on July 7, 2025.
What Information Was Exposed?
The attackers accessed both personally identifiable information (PII) and protected health information (PHI) related to Blue Cross Blue Shield of Massachusetts members, including:
- Full name and postal address
- Date of birth
- Social Security number and government ID numbers
- Health-plan beneficiary and medical record numbers
- Plan member account & claims numbers
- Provider names and treatment-related dates
- Premium details and generic service descriptions
- Financial information
Who Is Impacted?
Current and former members of Blue Cross Blue Shield of Massachusetts whose data Cierant processed for high-volume member mailings are potentially affected. If you received a notification letter dated July 3, 2025 (or later) from Cierant or the health plan, you are within the impacted population.
Cierant’s Response & Free Services
- 12 months of complimentary Epiq credit monitoring and identity restoration assistance
- Dedicated call center: 877-841-3066, Monday–Friday, 9 AM–9 PM ET
- Security hardening initiatives, including patching Cleo VLTrader and enhancing endpoint monitoring
Your Legal Options
Data-privacy laws allow victims to pursue damages when negligent security leads to a breach. Individuals may be able to join a class action seeking reimbursement for:
- Out-of-pocket costs (credit freezes, professional fees, etc.)
- Time spent monitoring and remediating identity fraud
- Emotional distress and loss of privacy
- Future credit-monitoring expenses beyond the free year offered
Important: Deadlines apply. Preserve your legal rights by consulting counsel as soon as possible.
Steps to Protect Yourself After the Cierant Data Breach
- Enroll in Cierant’s free Epiq credit monitoring without delay.
- Check your bank, credit-card, and explanation-of-benefits statements for unfamiliar charges.
- Place a fraud alert or credit freeze with Equifax, Experian, or TransUnion.
- Beware of phishing emails, calls, or texts that reference the breach.
- Document any fraud-related expenses; you may need proof to claim reimbursement.
Frequently Asked Questions
How did the Cierant Corporation data breach occur?
Investigators traced the intrusion to a vulnerability in the Cleo VLTrader file-transfer software that CL0P ransomware actors exploited to steal files.
What should I do if I got a Cierant breach letter?
Sign up for the free credit monitoring, review your financial and medical statements, and consider placing a fraud alert or freeze. Preserve the letter for possible legal action.
Is Cierant offering identity theft protection?
Yes. Affected individuals receive 12 months of Epiq credit monitoring and identity-restoration services at no cost.
Can I sue Cierant Corporation for the breach?
Potentially. Victims may join or initiate a class action seeking compensation for financial losses, time, and emotional distress resulting from the incident.
What data about me might be on the dark web?
Leaked data could include your name, address, DOB, SSN, policy numbers, and treatment-related information, depending on what Cierant processed for the health plan.
Did Blue Cross Blue Shield of Massachusetts systems get hacked?
No. Current evidence indicates only Cierant’s environment was breached. However, BCBSMA member data was stored there for mail-merge services.