Arthur, the malicious attacker, discovered eccouncil video

Full Certification Question

Arthur, the malicious attacker, discovered the contact number of techsecure.com online and made a call, pretending to be a representative from a trusted technical support team. He informed an employee at techsecure that one of their servers was at risk of being compromised and guided them through a series of steps. The employee unknowingly ran suspicious commands and installed harmful software, enabling Arthur to extract sensitive information and transfer it to his own system. Which social engineering technique did Arthur use in this scenario?