Major U.S. pharmaceutical distributor AmerisourceBergen has disclosed that one of its subsidiaries' IT system was hacked following the Lorenz ransomware gang's leak of files claimed to be stolen from the firm and its presumably breached subsidiary MWI Animal Health, reports BleepingComputer. Immediate action has been undertaken by AmerisourceBergen to contain the disruption but the company said that it is still investigating whether the incident had compromised any sensitive data. "We immediately engaged the appropriate teams to limit the intrusion, contained the disruption, and took precautionary measures to ensure all systems were and are now clear of any intrusions," said AmerisourceBergen. While the stolen data was only recently posted, such a network breach may have happened months ago, as indicated by the November post data by Lorenz ransomware attackers, which have been exploiting critical Mitel telephony system vulnerabilities to facilitate corporate network compromise in recent attacks. AmerisourceBergen has not yet confirmed the legitimacy of the stolen files.