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According to the organization , no confidential information was lost or destroyed , including PHI , and the practice group never received a ransom demand or other communications from unknown persons .
 unknown persons: attacker; the practice group: victim
Given event type and trigger, please tell me the arguments of all the listed option. Output format is "name1: role1; name2: role2". 
Event type: ransom 
  Option: victim, attacker, payment method, attack pattern, damage amount, tool, time, price, place 
Text: {0} 
Answer:
 unknown persons: attacker; the practice group: victim