Montana hospital data breach leaks SSNs, medical and financial info

The Community Hospital of Anaconda this week confirmed it notified victims of an August 2024 data breach that compromised the following personal info:

• Names
• Social Security numbers
• Dates of birth
• State-issued ID numbers (e.g. driver’s licenses, passports, and military IDs)
• Financial account info
• Patient account numbers
• Medical record numbers
• Medicare and Medicaid numbers
• Treatment info
• Health insurance info

Ransomware gang Meow claimed responsibility for the breach shortly after it occurred. The group says it stole 540 GB of data and demanded a $120,000 ransom. To prove its claim, Meow posted images of what it says are files stolen from the Community Hospital of Anaconda.

The hospital has not stated how many people it notified. Based on the info in Meow’s images, SuspectFile estimates more than 7,000 patients might be affected, plus hospital staff.

The Community Hospital of Anaconda has not verified Meow’s claim. We do not know if the hospital paid a random or how attackers breached the hospital’s network. Comparitech contacted the hospital for comment and will update this article if it replies.

“On August 12, 2024, CHA became aware of unusual activity that disrupted access to certain IT systems,” says CHA’s notice to victims. “The investigation revealed that an unknown actor may have accessed or acquired certain data from the CHA network between August 10 and August 12, 2024.”

The notice does not mention any offer of free credit monitoring or identity theft protection for victims.

Who is Meow?

Meow is a ransomware gang that first started claiming attacks in November 2023. Its ransomware builds upon Conti, an older strain. Meow steals data and holds it for ransom, but it might not encrypt files. Data theft and extortion without encryption is an increasingly popular trend among ransomware gangs.

Meow has taken credit for 19 confirmed ransomware attacks in total, but hasn’t added any new claims to its data leak site so far in 2025. Prior to 2025, it made another 124 unconfirmed claims that weren’t acknowledged by the targeted organizations.

In its confirmed attacks, Meow breached nearly 173,000 records. Its average ransom is $112,000.

CHA is not Meow’s first target in healthcare. The group attacked Vanderbilt University Medical Center in November 2023, the Physical Medicine Rehabilitation Center in July 2024, and Zydus Pharmaceuticals in July 2024.

Ransomware attacks on US healthcare

Comparitech researchers logged 161 confirmed ransomware attacks on US hospitals, clinics, and other direct care providers in 2024, compromising 27.2 million records. The average ransom was $1.05 million.

Other recently confirmed attacks from 2024 include:

• Weiser Memorial Hospital last week confirmed it notified 34,249 people of a September 2024 data breach claimed by Embargo
• Drug and Alcohol Treatment Service notified 22,215 people of an October 2024 data breach claimed by Interlock
• Neurological Spine Institute of Savannah notified 32,548 people of a June 2024 data breach claimed by RansomHub

In 2025 to date, we’ve logged 24 confirmed attacks and 86 unconfirmed claims.

Ransomware attacks on US hospitals, clinics, and other care providers can cripple key systems and endanger the health, privacy, and security of patients. Hospitals must pay a ransom or face extended downtime, data loss, and putting patients and staff at increased risk of fraud. Hospitals and clinics might have to resort to pen and paper, cancel appointments, and divert patients elsewhere until systems are restored.

About the Community Hospital of Anaconda

The Community Hospital of Anaconda is a 25-bed critical access hospital in Anaconda, Montana. It employs more than 60 physicians and 400 employees, according to its website.