B. Check WHOIS and netblock records for the company.
Explanation:
• WHOIS and netblock records provide essential information about the ownership of IP addresses, domain names, and associated netblocks. This information is publicly available and helps identify the scope of the company’s external-facing assets without alerting the company’s defenses.
• WHOIS queries can reveal details about domain registration, including contact information, which might give insights into the organization’s structure.
• Netblock records will help identify the range of IP addresses allocated to the company, which is critical for mapping the external network perimeter.