Host Enumeration via NetBIOS

On Windows, we can get information about the hosts under a network by interacting with the NetBIOS protocol

• We can use it to obtain the name table of a remote machine

nbtstat -a $hostname
nbtstat -a $IP

#Example output
...
Name               Type         Status
---------------------------------------------
WORKSTATION01  <00>  UNIQUE      Registered
WORKGROUP      <00>  GROUP       Registered    #Default group
WORKSTATION01  <20>  UNIQUE      Registered
...

---

• We could compare it to other hosts to identify if they are from the same or related domains, and even if they could belong to an Active Directory

nbtstat -a $hostname

#Example output
...
Name               Type         Status
---------------------------------------------
WORKSTATION02  <00>  UNIQUE      Registered
DOMAIN         <00>  GROUP       Registered    #Custom domain
WORKSTATION02  <20>  UNIQUE      Registered
DOMAIN2        <00>  GROUP       Registered    #Custom domain
...

---

• We could also generate a list of recently resolved NetBIOS names and their corresponding IP addresses to build a custom routing table

nbtstat -c

#Example output
...
Name               Type       Host Address    Life [sec]
--------------------------------------------------------
DOMAIN        <00>  GROUP     192.168.1.10    543
WORKGROUP     <00>  GROUP     192.168.1.255   340
...

---

• We could also check shared resources using the net view commmand

net view \\$IP /ALL

#Example output
...
Share name     Type   Used as  Comment
------------------------------------------
C$             Disk            Default share
SharedDocs     Disk            Shared documents     #Not default
...