Which type of tool would Alex use to check for vulnerabilities related to the Heartbleed bug?

To identify vulnerabilities related to the Heartbleed bug, using a vulnerability scanner is the most effective approach. Vulnerability scanners are designed to systematically assess systems and applications for known vulnerabilities, including specific exploits like Heartbleed. This is crucial because Heartbleed is a weakness in the OpenSSL cryptographic software library, allowing attackers to read sensitive data from memory.

Vulnerability scanners often come equipped with updated databases of known vulnerabilities and can automatically detect whether systems are exposed or susceptible to specific attacks, such as those related to Heartbleed. By deploying a scanner, Alex can quickly and efficiently evaluate the security posture of systems and ensure that they are not affected by this specific vulnerability, thus enabling timely remediation.

In contrast, while a packet sniffer could capture network packets, it would not inherently identify vulnerabilities; it is better suited for real-time traffic analysis. A network analyzer provides insights into network traffic and performance but does not focus specifically on security vulnerabilities. A firewall tester usually assesses the rules and configurations of firewalls rather than identifying vulnerabilities in systems or software itself.