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Login and Remote Access Attempts Failed

Overthere
Overthere asked
on
I'm new to Windows Server 2008 and I need assistance with securing the server from attacks of failed login attempts.  For several hours at a time, someone is trying to login to the server using winlogin.exe with various names and passwords.  They all fail.  Below is a copy of a line from the event viewer:

SECURITY LOG:  Audit Failure

An account failed to log on.

Subject:
      Security ID:            SYSTEM
      Account Name:            DEDICATED-SERVER$
      Account Domain:            WORKGROUP
      Logon ID:            0x3e7

Logon Type:                  10

Account For Which Logon Failed:
      Security ID:            NULL SID
      Account Name:            administrator
      Account Domain:            DEDICATED-SERVER

Failure Information:
      Failure Reason:            Unknown user name or bad password.
      Status:                  0xc000006d
      Sub Status:            0xc000006a

Process Information:
      Caller Process ID:      0xfa8
      Caller Process Name:      C:\Windows\System32\winlogon.exe

Network Information:
      Workstation Name:      DEDICATED-SERVER
      Source Network Address:      68.193.12.87
      Source Port:            3561

Detailed Authentication Information:
      Logon Process:            User32
      Authentication Package:      Negotiate
      Transited Services:      -
      Package Name (NTLM only):      -
      Key Length:            0

This event is generated when a logon request fails. It is generated on the computer where access was attempted.

The Subject fields indicate the account on the local system which requested the logon. This is most commonly a service such as the Server service, or a local process such as Winlogon.exe or Services.exe.

The Logon Type field indicates the kind of logon that was requested. The most common types are 2 (interactive) and 3 (network).

The Process Information fields indicate which account and process on the system requested the logon.

The Network Information fields indicate where a remote logon request originated. Workstation name is not always available and may be left blank in some cases.

The authentication information fields provide detailed information about this specific logon request.
      - Transited services indicate which intermediate services have participated in this logon request.
      - Package name indicates which sub-protocol was used among the NTLM protocols.
      - Key length indicates the length of the generated session key. This will be 0 if no session key was requested.

Plus in the System log I receive the following over and over again:

SYSTEM LOG: Event 1012, TerminalServices-RemoteConnectionManager

Remote session from client name a exceeded the maximum allowed failed logon attempts. The session was forcibly terminated.

I need to connect to this dedicated server via Remote Desktop Connection to maintain my websites, etc.  So turning off RDP is not an option.  The server holds .asp pages for a served CRM application that accesses SQL Server.  

I have paid for a hardware firewall setup. I notice that during the time periods when someone is trying to login to the server that my pages are not as fast and it's interferring with the speed of the system.

Any suggestions are appreciated.
Comment
Watch Question

The best route would be to configure your firewall to block all RDP connections with an exceptions list.  Of course, the IP address(es) you connect from would be included in this exceptions list.  If your IP is dynamically assigned you are generally able to specify a network address range.  If you need to find your ISP's network range, you may look-up your public IP on ARIN and reference the NetRange indicated.

What is the make/model of your firewall?  With the proper ACL requests will be blocked at the firewall and your servers performance won't be impacted.

Remember defense in depth is key; so in addition I'd also look-up various RDP security best practices, etc.

Author

Commented:
Giving that a try.  THANKS!

Commented:
The easiest way would be to move RDP access to a non-standard port. The automated cracking bots generally only look for default ports (3389 for RDP, in this case). Does the server have a public IP address assigned directly to the network card, or is the firewall doing NAT to a private network?