Automatically Reset the FTP Service in Windows Server 2008

Monday, March 3, 2008

One of the more popular tips I've posted is, "How to automatically reset the FTP service," in Windows Server 2003. This tip is useful for public FTP sites where bad guys are trying to hack in, usually using a dictionary attack.

Doing the same thing in Windows Server 2008 is slightly different and has an important caveat - It will not work with the Microsoft FTP Publishing Service for IIS 7.0 yet. It will work fine if you use the standard FTP Publishing Service, included on the Windows Server 2008 DVD.

As in my original post, create a batch file named C:\Scripts\ResetFTPService.bat, as follows:
net stop msftpsvc
ping -n 10 127.0.0.1
net start msftpsvc
The batch file stops the FTP service, pings the loopback adapter 10 times to create a 10 second pause, and starts the FTP service again. Stopping the FTP service causes the hacker's session to be dropped immediately. Since no one can connect for 10 seconds, this creates a form of "tarpitting", making it too expensive to continue the attack.

To make the script run automatically on the correct event, use the Windows Server 2008 Task Manager:

  • Right-click Task Manager (under Configuration in Server Manager) and select Create a Basic Task

  • Name the task, "Reset FTP Service" and click Next

  • Choose When a specific event is logged as the Task Trigger, click Next

  • Select Log: System, Source: IIS-FTP, and Event ID: 100. Click Next

  • Select Start a program and click Next

  • Enter C:\Scripts\ResetFTPService.bat for the Program/script and click Next

  • Click the checkbox for Open the Properties dialog for this task when I click Finish and then click Finish

  • In the Properties window select Run whether user is logged on or not and Run with highest privileges

  • Click OK

  • Enter the User name and Password for running this task

This causes the ResetFTPService.bat batch file to run whenever an event ID 100 with source IIS-FTP is logged in the System event log.

Remember, this will not work with the Microsoft FTP Publishing Service for IIS 7.0 because this service strangely does not log failed logon attempts to the event log. I've posted a request to the IIS7 team for this functionality.