IP Ban Utility by Digital Ruby

Recently we commissioned a new CMS server for one of our client, although it mostly locked down, we noticed lot of failed login attempts in Windows Event Viewer.

If you go to Event Viewer -> Windows Logs > Security log and then filter for event id 4625 (Logon), you will be able to see login event (both success and failed). Audit failure events shows failed login attempts.

Relate to that 4740 (User Account Management) shows if above failed login attempts caused windows to lock down your account (in case hacker identified one of your account).

So how to prevent this. Most appropriate thing is to remove it from from public access. But server like CMS server need expose to internet. In that case you can lock down RDP and other access methods and just open web traffic. However, there are instances where servers need to be open for public traffic/access, specially if thirdparty is working on them (continuously).

In that case, you can restrict access to known IP addresses, or use VPNs.

If every method is un-available to you, I found out there is another option. That is banning IPs that un-authorized login attempts are coming. You can do this in your firewall.

But hardest thing is hackers change their IPs randomly, when you block one IP they come from another.

I found this elegant peice of software developed by Digital Ruby software house. It is called IP Ban. Process is simple. It monitor the event log for failed login attempts and if it exceed number you specified (from a particular IP), then it add a firewall rule to stop traffic from that IP address.

IPBan is available free on Github -> https://github.com/digitalruby/ipban

You can download it from here -> https://github.com/DigitalRuby/IPBan/releases

More information about developer can be found here -> https://www.digitalruby.com/server-software/

If you need pro version, this is the place to buy -> https://ipban.com/products

IPBan works on both Windows and Linux servers.

Installation is easy (run following in PowerShell):

$ProgressPreference = 'SilentlyContinue'; [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; iex "& { $((New-Object System.Net.WebClient).DownloadString('https://raw.githubusercontent.com/DigitalRuby/IPBan/master/IPBanCore/Windows/Scripts/install_latest.ps1')) } -startupType 'delayed-auto'"

It is getting installed as Windows Service (IPBan). You can find the program in default insallation location "C:\Program Files\IPBan".

There is a xml config file on installation directory, where you can change many settings. But mostly default settings works. 

One of the interesting settings is "Whitelist" setting, which allows you to specify comma seperated list of IPs to avoid banning. Make sure to set this for one of your sever, so in case something goes wrong you can log on from there.

It adds Firewall rules prefixed with "IPBan_" so it is easy to identify. You can change the prefix if you prefer something else.

Usually ban is held for 1 day, but you can change this setting.

Adding Windows Firewall Rules to a Group

Anyone who has used windows firewall, knows it is easier to create rules and configure, but hard to organize.

Though Windows Advanced Firewall interface shows a Group column, there is no easy way to set the group through UI.

In a recent task assigned to me, I wanted to organize my rules to several groups, that's when Powershell came in handy.

Let's say I have 5 rules I need to group. Currently they don't have a group.

I want to assign Rule 1, 2 and 3 to "My Group 1" and rule 4 and 5 to "My Group 2".

Get-NetFirewallRule -DisplayName 'My Rule 1' | ForEach { $_.Group = 'My Group 1'; Set-NetFirewallRule -InputObject $_ }

Get-NetFirewallRule -DisplayName 'My Rule 2' | ForEach { $_.Group = 'My Group 1'; Set-NetFirewallRule -InputObject $_ }

Get-NetFirewallRule -DisplayName 'My Rule 3' | ForEach { $_.Group = 'My Group 1'; Set-NetFirewallRule -InputObject $_ }

Get-NetFirewallRule -DisplayName 'My Rule 4' | ForEach { $_.Group = 'My Group 2'; Set-NetFirewallRule -InputObject $_ }

Get-NetFirewallRule -DisplayName 'My Rule 5' | ForEach { $_.Group = 'My Group 3'; Set-NetFirewallRule -InputObject $_ }

So in the firewall rule, first you fetch the firewall rule by using Get-NetFirewallRule cmdlet. Then for each result, you set the group to bying using $_.Group.

Result: