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The same thing happened in 2015 , in a series of attacks called RansomWeb , where attackers used unpatched phpBB forums to hijack databases and hold websites up for ransom .
 ( ransom: ransom,  hold websites: attack pattern, used unpatched phpBB forums to hijack databases: attack pattern, attackers: attacker) 
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:
 ( ransom: ransom,  hold websites: attack pattern, used unpatched phpBB forums to hijack databases: attack pattern, attackers: attacker) 