3747
The Russian firm is said to have extensive technical experience in security vulnerabilities of supervisory control and data acquisition systems that are used to remotely control critical infrastructure .
 ( discover vulnerability: said,  security vulnerabilities: vulnerability, supervisory control and data acquisition systems: vulnerable system, remotely control critical infrastructure: capabilities, The Russian firm: discoverer) 
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: said,  security vulnerabilities: vulnerability, supervisory control and data acquisition systems: vulnerable system, remotely control critical infrastructure: capabilities, The Russian firm: discoverer) 