Byteware Solutions is a small tech startup that recently experienced a data breach. After resolving the incident, the company’s cybersecurity expert runs vulnerability scans to check for any remaining vulnerabilities. But for extra assurance, the company hires Mateus, an outside cybersecurity consultant. Mateus uses real hacking techniques to test system and network security. He discovers several vulnerabilities that the vulnerability scans missed and reports his findings.Which cybersecurity role does Mateus have in this scenario?