Deanco Healthcare LLC, which does business as Mission Community Hospital (MCH) in California, has issued a breach notification about a ransomware attack it discovered in early May.
According to their notification to the California Attorney General’s Office, MCH was alerted to potential unauthorized access to its IT network on May 1, 2023. Investigation confirmed that there was unauthorized access on that date.
“While in our IT network, the unauthorized party accessed files containing patient information. Our investigation cannot rule out the possibility that, as a result of this incident, files containing some of your information may have been subject to unauthorized access,” patients were informed.
“This information may have included your address, date of birth, Social Security number, driver’s license number, financial account information, health insurance plan member ID, claims data and clinical information about your care with Mission Community Hospital.”
Those notified of the incident were offered one-year membership to Experian®’s IdentityWorksSM.
MCH’s letter omits some details that patients might consider significant to consider. Of particular note, this was a ransomware attack by RansomHouse threat actors, who listed the incident on their dark web leak site on May 31. The threat actors claimed that they had locked MCH’s files on April 29 and exfiltrated 2.5 TB of data. A small proofpack included three screencaps of directories that appear to indicate that the attackers were connecting via remote desktop protocol. The screencaps were dated April 16, 2023, approximately two weeks before the attackers deployed the ransomware.
Based on MCH’s notification, MCH never detected RansomHouse in their network until it was too late.
RansomHouse’s listing claims that they encrypted data. Image: DataBreaches.net.
On May 31, DataBreaches emailed MCH to ask them about the incident. MCH did not reply to DataBreaches’ inquiries. On June 30, MCH notified HHS of the incident, reporting that 500 patients were affected. The “500” is a marker to show the entity knows more than 500 patients were affected but they do not yet know the actual number. The number on HHS’s breach tool remains at 500, so we do not yet know how many patients were really affected.
When RansomHouse added MCH to their leak site, they added a note:
Dear Mission Community Hospital Management, We strongly recommend you to contact us to prevent your confidential data or research data to be leaked or sold to a third party.
RansomHouse’s listing remains on their dark web site. It has not been updated with any data leak or further message. Did they sell the data privately or leak it somewhere? MCH’s notification provides patients with no information about these possibilities.