Amanda’s primary enumeration focus is a “file transfer” service that allows anonymous login and directory listing. That clearly indicates FTP, which runs on TCP port 21 (control channel). Anonymous FTP misconfiguration is a well-known exposure risk because it can allow unauthenticated users to browse or download files, and sometimes even upload content depending on permissions. Enumerating FTP typically includes validating anonymous access, listing directories, checking readable file contents, identifying writable folders, and verifying whether the server leaks banners, system type, or user/account hints.
The scenario also mentions background UDP traffic related to NetBIOS name lookups, which corresponds to UDP port 137 (NetBIOS Name Service). While NetBIOS is more common in Windows environments, it can still appear on networks with mixed systems or legacy compatibility services. The question asks which ports and services to prioritize given her enumeration activity, which includes FTP access weaknesses and noticing NetBIOS name lookup traffic.
Option B (TCP 21 and UDP 137) matches both:
TCP 21 = FTP control port, directly tied to anonymous login and directory enumeration.
UDP 137 = NetBIOS Name Service, matching the observed name-lookup traffic.
Why the other options don’t fit:
TCP 23 is Telnet (A), not the described file transfer service.
TCP 25 is SMTP (C), unrelated to anonymous file transfer login.
TCP 139 is NetBIOS Session Service (D), more associated with SMB over NetBIOS, not specifically with UDP name lookups, and it omits the FTP port central to her activity.
Therefore, the correct choice is B. TCP 21 and UDP 137.
