3719
Specifically , researchers found an Android version of X-Agent , a piece of malware known to be used by Fancy Bear , embedded in an app developed by artillery officer Yaroslav Sherstuk to help military personnel reduce the time to fire D - 30 howitzers .
 ( discover vulnerability: found,  artillery officer Yaroslav Sherstuk: vulnerable system owner, researchers: discoverer, an app: vulnerable system, X-Agent: vulnerable system, Android: supported platform) 
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,  artillery officer Yaroslav Sherstuk: vulnerable system owner, researchers: discoverer, an app: vulnerable system, X-Agent: vulnerable system, Android: supported platform) 