2004
“ This means that even if an attacker found a new zero - day technique for injecting code , it could not be used against the antivirus as its code is not signed .
 ( discover vulnerability: found,  injecting code: vulnerability, an attacker: discoverer, a new zero - day technique: vulnerability) 
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:
 ( discover vulnerability: found,  injecting code: vulnerability, an attacker: discoverer, a new zero - day technique: vulnerability) 