SCSC 555Frank Li
Introduction to Enumeration Enumerate Microsoft OS Enumerate *NIX OS Enumerate NetWare OS (skip)
2
Enumeration extracts information about:◦ Resources or shares on the network◦ User names or groups assigned on the network◦ Last time user logged on◦ User’s password
Enumeration is more intrusive than passive port scanning◦ First need to determine OS of the target host
By Port scanning and footprinting◦ E.g. NBT (NetBIOS over TCP/IP) is the tool for
enumerating Microsoft OSs
3
Using enumeration tool nbtscan◦ Use nbtscan command to scan a range of IP
addresses ◦ Example: nbtscan 192.168.0.0./24
4
Introduction to Enumeration Enumerate Microsoft OS Enumerate *NIX OS
5
Study OS history◦ Knowing your target makes your job easier◦ Many attacks that work for older Windows OSs
still work with newer versions
6
7
8
Network Basic Input Output System (NetBIOS)◦ Is a MS programming interface◦ Allows computer communication over a LAN◦ Used to share files and printers
NetBIOS names are computer names assigned to Windows systems◦ Must be unique on a network◦ Limit of 16 characters◦ The last character (suffix) is reserved for identifies
type of service running next page
9
10
11
One of the biggest vulnerabilities of NetBIOS system -- NetBIOS Null session◦ Is unauthenticated connection to a Windows
computer Does not use logon and passwords values
Attackers use enumeration tool to establish a null session ◦ to gather logon accounts, group membership, and
file shares from target hosts
12
NetBIOS NULL sessions are enabled by default in Windows NT and 2000.
Windows XP and 2003 will allow anonymous enumeration of shared network resources, but not accounts.
13
For the most part if the appropriate ports are accessible a NULL session is possible.
14
Port Protocol Description
135 TCP Location Service (RPC endpoint mapping)
135 UDP Location Service (RPC endpoint mapping)
137 TCP NETBIOS Name Service
137 UDP NETBIOS Name Service
138 TCP NETBIOS Datagram Service
138 UDP NETBIOS Datagram Service
139 TCP NETBIOS Session Service
139 UDP NETBIOS Session Service
445 TCP SMB/CIFS
Use IP address obtained when port scanning to perform a NetBIOS enumeration
NetBIOS Enumeration Tools◦ Nbtstat◦ Net view◦ Net use◦ NetScanTools Pro◦ DumpSec◦ Hyena◦ NessusWX◦ Enum◦ Hunt
15
Nbtstat command◦ Powerful enumeration tool included with the Microsoft OS◦ Displays NetBIOS table◦ E.g., Nbstat –a salesrep
16
Net view command◦ Shows whether there are any shared
resources on a network host E.g., net view \\192.168.0.106
17
Net use command◦ Used to connect to a computer with shared
folders or files◦ view the information about current computer
connections. ◦ also can controls persistent network connections.
E.g., To assign the disk-drive device name E: to the Letters shared directory on the \\Fin server, type: net use e: \\fin\letters
18
NetScanTools Pro produces a graphical view of NetBIOS running on a network◦ Enumerates any shares running on the computer◦ Verifies whether access is available for shared
resource using its Universal Naming Convention (UNC) name
◦ Example: figure 6-10, 6-11 the \\SALEsMGR\SharedDocs comment entry is blank.
to see whether access is available, an attacker enters the UNC \\SALEsMGR\SharedDocs in the Run dialog ox in Windows
19
DumpSechttp://www.systemtools.com/cgi-in/download.pl?DumpAcl
Produced by Foundstone, Inc. Allows user to connect to a server and “dump”
the following information◦ Permissions for shares◦ Permissions for printers◦ Permissions for the Registry◦ Users in column or table format◦ Policies and rights◦ Services
20
Hyena is GUI product for managing and securing Microsoft OSs◦ Shows shares and user logon names for
Windows servers and domain controllers◦ Displays graphical representation of:
Microsoft Terminal Services Microsoft Windows Network Web Client Network Find User/Group
21
NessusWX allows enumeration of different OSs on a large network
Running NessusWX1. Nessus server is up and running2. Open the NessusWX client application3. To connect your NessusWX client with the
Nessus server1. Click Communications, Connect from the menu on
the session window2. Enter server’s name3. Log on the Nessus server
22
23
24
Enum http://www.bindview.com/Services/RAZOR/Utilities/Windows/enum_readme.cfm
one of the best tools for exploiting the NULL session vulnerability
allowing you to exploits every aspect of this flaw. ◦ the ability to enumerate users, ◦ and then try to brute force the password using a supplied
password list.
25
Hunt http://www.foundstone.com/resources/freetools/hunt.zip
Part of the NT Forensic Toolkit from Foundstone,
this tool makes it very easy to enumerate users and shares from a vulnerable windows host, and is the most accurate
26
Nessus identifies ◦ NetBIOS names in use◦ Shared resources◦ Password information
27
28
29
30
Nessus also identifies:◦ OS and service pack◦ OS vulnerabilities◦ Firewall vulnerabilities
31
32
33
34
Introduction to Enumeration Enumerate Microsoft OS Enumerate *NIX OS
35
variations of Unix◦ Solaris◦ SunOS◦ HP-UX◦ Linux◦ Ultrix◦ AIX◦ BSD UNIX◦ FreeBSD◦ OpenBSD
36
Finger utility◦ Is the most popular tool for security testers◦ Finds out who is logged in to a *NIX system◦ Determine owner of any process
Nessus can also be used for *NIX enumeration
37
E.g., # finger -b -p james
display the following information about the user james.Login name, Computer Hope on since Feb 11 23:37:16 on pts/7 from domain.computerhope.com28 seconds Idle TimeUnread mail since Mon Feb 12 00:22:52 2001
38