Last week, the US government warned that hospitals across the US have been targeted by an aggressive ransomware campaign originating from North Korea since 2021.

Ransomware hacks, in which attackers encrypt computer networks and demand payment to make them functional again, have been a growing concern for both the private and public sector since the 90s. But they can be particularly devastating in the healthcare industry, where even minutes of down time can have deadly consequences, and have become ominously frequent.

The number of ransomware attacks on healthcare organizations increased 94% from 2021 to 2022, according to a report from the cybersecurity firm Sophos. More than two-thirds of healthcare organizations in the US said they had experienced a ransomware attack in 2021, the study said, up from 34% in 2020.

Ransomware attacks on healthcare are particularly common in the US, with 41% of such attacks globally having been carried out against US-based firms in 2021.