Alex, a malicious hacker, set his sights on TechGuard Corporation, a multinational company. His objective was to identify IoT devices within the target network that might be susceptible to hijacking due to their use of default credentials. To achieve this goal, he employed an automated tool designed to scan the target network, specifically seeking out certain types of IoT devices and identifying whether they were utilizing the default credentials set by the manufacturer. What is the name of the tool utilized by Alex in this scenario?