In recent weeks, hackers’ malware targets have included Boston Children’s Hospital, the Champaign-Urbana Public Health District in Illinois and a university hospital in the Czech Republic. Hackers have also tried to shut down systems at a couple of Canadian medical institutions by pretending to be from the World Health Organization, according to a new report from cybersecurity firm Palo Alto Networks’ Unit 42 research division.

Hospital workers during the COVID-19 health emergency may be particularly vulnerable to malicious emails, as Unit 42 deputy director Jen Miller-Osborn told The Washington Post. “People are stressed, and it might short-circuit the logic in their brain that says I shouldn’t click that,” Miller-Osborn said. In early April, Interpol warned its 194 member countries of a heightened ransomware threat toward hospitals. The U.S. Department of Homeland Security, in a more generalized alert, cited ransomware attacks on hospitals and health organizations in America and across Europe.

Key lawmakers, including Sen. Mark Warner (D-Va.) and Sen. Michael Bennet (D-Colo.), are sounding the alarm about the cybersecurity threats against hospital systems, as The Hill reports. An alliance of major tech organizations, in urging Congress to increase state cybersecurity funding amid the pandemic, also pointed to worries about hospitals.

In 2019, 83% of healthcare groups saw an uptick in cyber attacks, with 66% saying the attacks were growing more complex, as The Boston Globe reports, citing a survey by cybersecurity firm VMware Carbon Black. According to the survey, 764 healthcare providers experienced malware attacks last year. At the same time, healthcare groups typically allocate only 3% to 4% of their information technology spending to cybersecurity, a tiny share compared with industries such as financial services, said David Finn, EVP at cybersecurity company CynergisTek and a former chief information officer at Texas Children’s Hospital.

As the Pew Charitable Trust’s Stateline service reports, other ransomware victims from the healthcare sector so far this year include a nonprofit Rochester, N.Y., health system that runs nine health centers and California biotech firm 10X Genomics. Microsoft recently issued what it called a “first-of-its-kind targeted notification,” tipping off “several dozens of hospitals” about software flaws. The Greater New York Hospital Association has also warned members of an “active cybersecurity threat.”