Phishing operation attacking at least 20 health care organizations disrupted by Microsoft

Microsoft Sept. 16 announced it had disrupted a growing phishing service that had targeted at least 20 U.S. health care organizations. The company said it used a court order granted by the U.S. District Court for the Southern District of New York to seize 338 websites associated with RaccoonO365, a cyber threat group known for stealing Microsoft 365 credentials through phishing tactics. RaccoonO365 offers subscription-based phishing kits that allow individuals to steal Microsoft credentials by mimicking official Microsoft communications. The company said the phishing kits use Microsoft branding to create fraudulent emails, attachments and websites. Since July 2024, the kits have stolen at least 5,000 Microsoft credentials from individuals in 94 countries. The group was recently observed offering a new artificial intelligence-powered service in an attempt to scale their operations.

“Credentials stolen through RaccoonO365 enabled ransomware attacks against hospitals, posing a direct threat to patient and community safety,” said John Riggi, AHA national advisor for cybersecurity and risk. “This operation also highlights a disturbing trend — cybercriminals’ increased use of ‘initial access brokers’ to steal credentials and AI to accelerate the effectiveness, sophistication and impact of cyberattacks. The need for continued and evolving social engineering training for staff is essential to defend against the latest deception tactics used by hackers.”

For more information on this or other cyber and risk issues, contact Riggi at jriggi@aha.org. For the latest cyber and risk resources and threat intelligence, visit aha.org/cybersecurity.