Posts

Syspeace for internal brute force protection on Windows Servers

After installing Syspeace , the tech guys started getting notifications that their Exchange Server was trying to login to another server and it was rejected. There was no reason for this server to do so whatsoever and it had not been noticed earlier so it’s hard to say when it actually started.

After disabling the whitelist for the LAN at the customer site they started getting mail notifications that every workstation on their LAN was actually trying to login to various servers using various usernames and password, hence a brute force attack/dictionary attack from the inside.

Most likely a trojan has been planted somewhere and it has infected the rest.

This is a fairly simple example of how Syspeace can actually reveal a security breach a customer wasn’t even aware of had occured.

It is totally up to any customer to use whitelists for the LAN but as a precaution, I personnally wouldn’t recommend it since it acutally gives you a great heads up that something has happened if a computer or multiple computers suddenly starts to try and login to servers they’re not supposed to.

As a system administrator, you get the chance to get attack automatically blocked, logged, traced and reported and you can have a closer at the computer responsible for the attack or have a word the user to see what’s going on.

You can even create extensive reports on all activity originating from that user or computer using the Access Reports section in Syspeace to get a more clear view on how long it’s been trying and so on.

Since Syspeace automatically protects failed logins using Winlogon authentication, your Windows servers are also protected from computers/users trying to use the “net use” or “map network drive” with invalid logon credentials trying to acces shares they’re not supposed to.

If you don’t have processes in place for scanning logs, saving them and monitoring every login activity, it will become grusome task to even know if there’s something going on at all. You simply won’t have the tools to do so.

Have your own servers run the fully functional Syspeace free trial and see if you get any unexpected login failures from the internal network and from Internet.
You might be surprised.

By Juha Jurvanen

Am I under attack for a brute force or dictionary attack on my Windows server?

Brute force attack or dictionary attack on Windows servers

Dictionary attack and Brute force attack are fairly easy to find out if your Windows servers are being hit with some sort of an attack.

Simply enable auditing of Logon Events in your Security Policy and look at the eventviewer and see what pops up. You will then know if your server are hit by brute force or dictionary.

Dictionary or Brute force in the eventviewer

Open your eventviewer and search for logon events named 4625 n Windows 7, Vista, 2008 , 2008 R2, 2012, 2012 R2 or 529 on Windows server 2003.

Open up these events and look at the username used, the network source address and see if they are legitimate login attempts or not.
You could use for instance WHOIS to find out where the attack came from or traceroute or nslookup.

How do you single out dictionary or Brute force attack?

If you’re under attack you’ll be seeing hundreds or thousands of failed logon attempts, sometimes from a single IP address or in a more serious scenario, from hundreds or even thousands IP addresses at once.

In some cases, such an attack is also just a way to hide the real purpose behind the attack which is to find out what security measures you have in place and to search for any vulnerabilities you may have in place that can be use to hack you later on. The attacker tries to “hide in the noise” so to speak.

If it’s a single IP address it’s fairly easy just to block the attacker in your external firewall completely or in the local Windows firewall (assuming you’re awake and have seen the attack ) but, if it’s hundreds or thousands at once it becomes more or less impossible if you can’t automate it.

This is where Syspeace comes into play.

Syspeace – The innovative tool for Brute force and Dictionary attacks

Syspeace automatically monitors, traces, blocks and reports failed logon events if they reach the criteria you’ve set up, for example “If an attacker fails to login 10 times during 30 minutes, I want the attackers IP address to be blocked completely on all ports for 2 hours” or even “If an IP address fails to login more than 10 times during 7 days, I want the attacker to be blocked ..”

If you’re under attack, the fastest and easiest way is to download the free trial of Syspeace, install it and simply start the Syspeace service and the attack will be blocked automatically within minutes.

At the moment, Syspeace supports Windows 2003, 2008, 2008 R2, 2012, 2012 R2 and all of the SBS versions, SQL Server, Exchange Server, Citrix and more.
Out of the box.
And there’s a fully functional, free 30 day trial on the website. We help you check for brute force attack and dictionary attack the easy way.