139,445/tcp - SMB
Enumeration
SMB can provide a lot more than just file sharing
Start with CrackMapExec, which is a pretty well rounded tool for most things you’d ever want to do with SMB
Enum system attributes as either an authenticated user or in an unauthenticated session.
enum4linux -a [-u '<username>' -p '<passwd>'] <IP>
Mount a Share
mount -t cifs //<target_ip>/<sharename> <mount_point> # unauthenticated
mount -t cifs -o "username=user,password=password" //<target_ip>/<sharename> <mount_point> # username/password auth