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of Defense subcontractor , was the source of a large data exposure of military personnel files of physical and mental health support staff .
 ( data breach: a large data exposure,  personnel files: compromised data, Defense subcontractor: victim, staff: victim, military: victim) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: phishing, data breach, ransom, discover vulnerability, patch vulnerability, Arguments type: vulnerable system, capabilities, vulnerability, number of victim, issues addressed, compromised data, damage amount, common vulnerabilities and exposures, victim, patch number, number of data, tool, discoverer, time, purpose, place, payment method, releaser, vulnerable system version, attacker, supported platform, patch, price, vulnerable system owner, trusted entity, attack pattern. 
Text: {0} 
Answer:
 ( data breach: a large data exposure,  personnel files: compromised data, Defense subcontractor: victim, staff: victim, military: victim) 