ISTANBUL

Hackers have stolen the personal data of hundreds of thousands of Dutch citizens from a medical laboratory in the city of Rijswijk, Dutch media reported Monday.

The hacker group Nova said on the dark web that it had obtained data from Clinical Diagnostics and threatened to publish the information if its demands are not met.

According to broadcaster RTL Nieuws, the hackers had previously received a payment from Clinical Diagnostics to prevent an earlier release of stolen data.

The group now claims the company “violated agreements,” possibly by involving police, and has issued a new ultimatum. A countdown clock gives the firm until the night of Aug. 28 to comply.

They threatened to publish the information unless paid 11 bitcoins, equivalent to almost €1.1 million ($1.28 million).

The breach involves highly sensitive information from 485,000 women who participated in the national cervical cancer screening program, including names, addresses, dates of birth, citizen service numbers (BSN), and in some cases test results.

The hackers have already published data belonging to more than 50,000 people, including results from other medical examinations such as vaginal, penile, urine, skin tissue, or wound fluid studies.

Nova claims to have stolen around 300 gigabytes of data, though only 85 megabytes — about 0.03% — has so far been posted online as a sample.