UAT-10027 Targets U.S. Education and Healthcare with Dohdoor Backdoor

A previously undocumented threat activity cluster has been attributed to an ongoing malicious campaign targeting education and healthcare sectors in the U.S. since at least December 2025. The campaign is being tracked by Cisco Talos under the moniker UAT-10027. The end goal of the attacks is to deliver a never-before-seen backdoor codenamed Dohdoor. "Dohdoor utilizes the DNS-over-HTTPS (DoH)