1087
In January and February , a group calling itself Stealth Ravens launched DDoS - for - Bitcoin ransom attacks .
 Stealth Ravens: attacker; a group: attacker; February: time; January: time
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:
 Stealth Ravens: attacker; a group: attacker; February: time; January: time