Around 50 hospitals around the world are less likely to get popped in ransomware attacks this week, thanks largely to a loose band of InfoSec pros that banded together to help healthcare providers during the COVID-19 crisis.

While they aren’t yet going after ransomware gangs in vigilante-style retribution, the group’s pro bono work has already helped pinpoint over 50 healthcare organizations running vulnerable versions of Citrix NetScalers or Pulse Secure VPN gateways.

Vulnerable VPN endpoints have been targeted by several ransomware gangs in recent months, and despite promises from some groups not to target healthcare organizations, hospital networks and the medical supply chain continue to fall victim.

The voluntary threat intel and hunting effort has been welcome help for Errol Weiss, chief security officer at the Health Information Sharing and Analysis Center (H-ISAC), which has taken on the role of aggregating and disclosing vulnerability information collected by the group to affected healthcare providers.

The group of independent researchers - which now numbers around 200 - has no name. Most of its members prefer anonymity and volunteer outside of work hours. So far they have provided H-ISAC data from honeypots set up to detect opportunistic scanning activity. They also scanned the internet for IP addresses hosting vulnerable VPN endpoints, from which H-ISAC extracted a list of 50 healthcare providers. H-ISAC has sent those organisations links to technical write-ups on the vulnerabilities in question, as well as generic mitigation advice, irrespective of whether they are H-ISAC members.

Weiss is optimistic the advisories will be acted on. “Based on our prior experience, most [hospitals] will pay attention and do something,” he said. The hospitals will be prompted with further information if their systems continue to show up in scans, he said.

Ohad Zaidenberg, one of the few public figures working to corral volunteers, told Risky Business the group has only “just started.”

“From tomorrow, we will start to work actively,” he said, but was coy as to what the next phase of their program involves.

Healthcare CSOs we spoke to this week were grateful for the camaraderie and generosity of their industry peers. But they also cautioned to not expect too much of hospitals under strain.

“The offers of intel-sharing and threat hunting is only useful to the extent that hospitals have the capacity and capability to consume it,” said Christopher Neal, CSO of Ramsay Health Care, which operates a global network of 480 medical facilities in 11 countries. In most hospital networks, Neal said, there are insufficient resources available to act on the information - even prior to the coronavirus outbreak.

Neal wants to see “clearer public policy arguments to increase funding for security programs” in healthcare.

Weiss said that he is keen to receive more Indicators of Compromise (both atomic indicators and TTPs) about ransomware attacks, as well as decryption methods for various strains of the malware. But he recognizes the difficulties that might emerge as the initiative scales. Automation may be required to filter and sort through the volume of data coming in and to prepare actionable reports.

Still, he said, “I’d rather have that problem than the reverse.”