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The breach may be the most extensive since 2015 , when thieves gained access to the tax returns of over 300,000 people by using stolen data and filed fraudulent returns to get refunds .
 data breach: gained access
Please tell me event type and its trigger word from given type options. Output format is "type: trigger".  Option: phishing, data breach, ransom, discover vulnerability, patch vulnerability 
Text: {0} 
Answer:
 data breach: gained access