294,000 Allegheny Health Network Patients Affected by Business Associate Cyberattack. Allegheny Health Network (AHN), a Pittsburgh-based 14-hospital academic medical system, has announced a significant data breach involving unauthorized A data breach at a business associate of Allegheny Health Network has affected almost 294,000 of its home health patients. Pediatric Home Service has reported a 48,000 record data breach, and a ransomware attack on Alta Resources Corp. involved unauthorized access to the protected health information of 12,000 individuals. Third-party company: IntraSystems LLC.