Increasing Windows 2000 and XP Security
Windows 2000 and Windows XP are a very strong server
solution. Backwards compatibility, Microsoft's default assumptions,
and improper configurations have
created many security issues. There are a lot of unneeded services
installed in Windows 2K and XP that take up extra resources and
create security holes for hackers to attack your computer. This
article will identify common security threats and services to
disable.
This article is written mainly on information for Windows 2000
but many of the same threats are in Windows XP as well.
Windows Security Threats:
A properly configured Windows machine is a very secure
machine. Writing an article on security could entail thousands
of
pages for each setting and how to defend against each type of
attack. This article is meant to be a brief overview of the major
steps
a user or administer can take to gain a strong foothold in securing
their Windows computer.
Editing the registry and disabling services can lead
to problems. Make sure you double check all your edits and perform
a backup before making major changes. Only change one setting at
a time to allow for ease of recovery if a problem occurs.
Registry settings are edited with a program call
regedit32. Click on the Start Menu > Run > type regedt32
Services are turned on and off by the services.msc.
Clock on the Start Menu > Run > type services.msc
- Stop Null Sessions
- This is the biggest security threat to Windows. Null sessions
allow unwanted users to gain access to your computer. Null sessions
are opened on NetBIOS ports 139 and 445. NetBios
is Windows' default protocol for "File and Print Sharing." With
automated tools, hackers will gain access to crucial system information
such as accounts and passwords. NULL sessions are a built in
communication share using an anonymous user and a NULL password
on the NetBios
port.
-
- The easiest way to stop NULL session is by disabling "File
and Print Sharing" on all network devices. On XP go to Control
Panel
> Network Connections > Properties for each adapter. On
Windows 2000 go to Control Panel > Network and Dial-up Connections
and select the proper connection.
-
- If these services are required then make a registry entry to
protect from sending sensitive data through the NetBios port.
Open
regedt32 from the Run Menu. Select HKEY_LOCAL_MACHINE > System
> CurrentControlSet > Control > LSA. The key you want
to edit is RestrictAnonymous. Change the value
to a 1 or 2. A setting of 1 indicates that null connections
are
allowed but sensitive data is blocked being sent via the connection
(only option available in NT4). A setting of 2 will disallow
any
NULL connections; this may conflict with some 3rd party software.
There are a few hacking tools that will work on a level 1 setting
and retrieve information. Reboot the machine when done.
Another way to prevent access to port 139 is to disable NetBIOS
over TCP/IP. Windows will cascade to port 445 to respond to NULL
sessions and other requests.
- Disable SNMP services
- If null sessions are disabled, another easy way to gain system
information is through public SNMP.
If there are no programs using SNMP, disable this service. This
is the easiest way protect against hacks and free up some memory.
If SNMP access is needed, then set SNMP not to run in
a public mode. Open the registry editor. Go to HKLM > System
> CurrentControlSet > Services > SNMP > Parameters
> ValidCommunities. Select Security> Permissions and change
them to permit only approved users access.
There is one more step to disabling public access to SNMP. Go
to HKLM > System > CurrentControlSet > Services >
SNMP > Parameters > ExtensionAgents and delete the value
that contains the LANManagerMIB2Agent. Then rename the
other entries to update the sequence, ie. 2, 3 etc. until the
sequence begins with a 1.
- Disable Unused Services
- Disable all services that are not needed for system. Unused services
only take up resources and allow attackers to use them or come
through the ports they leave open.
Disable Alerter and Messenger if they are not used for they give
an attacker SYSTEM rights, basically the right to run anything
on your computer.
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