Tag Archives: network segmentation

US-CERT Ramsonware Reminder

If you have subscribed to the US-CERT alerts (and I sure hope you have!!), then you will have received today’s alert on “Ongoing Threat of Ransomware“. PLEASE read it!! Ransomware is getting worse…and it’s not going away anytime soon. This alert is more of a friendly reminder…a tap on your shoulder…to double check your policies and procedures, and make sure you are ready for a Ransomware event. I’m being very honest here…if you haven’t been hit yet, you will.

The alert mentions three main best practices…(with some of my thoughts)…

  • Create system back-ups: This is a no brainer! (I’ll assume you are backing up all of your critical systems and important data.) However, there is more to do…you need to regularly validate the integrity of those backups. Perform test restores and make sure you are comfortable with the processes. And make sure the back-ups are segmented from possible Ransomware attacks. Back-ups are worthless if they end up part of the Ransomware encrypted files.
  • Be wary of opening emails and attachments from unknown or unverified senders: Translated…TRAIN your users!! They are the first line of defense!! And you may groan at that thought, but I will tell you they WANT to be well trained! Just keep it simple and show them examples of what to expect (especially with phishing emails!). Send out regular reminders and make sure to publicly praise them as they catch this stuff…they will love it!!
  • Ensure that systems are updated with the latest patches:¬†Ladies and gentlemen…this is Network Administration 101. If you do not have a regular patch procedure in place, then shame on you!! Failing in this area can get you fired! Nuff said…

And I want to add one more “best practice”…¬† Segment your network: This is a huge undertaking…one that is a pain in the butt to be honest. But it can pay huge dividends if done right. Most of you will have a Ransomware event at some point (or other security event)…it’s going to happen. However, if you segment your network, you can greatly reduce the impact of an attack or hack.

Segmenting simply means to put in place policies that restrict what type of network traffic can flow where. A simple example is printers…every company has them (lots of them!). Yet most companies place them on the same network segments as the users…not good. You should place all of your printers in their own VLAN, and then apply a policy, such as an ACL (Access Control List) that allows the printers to talk just to the print-servers, and nowhere else. Another example is SQL servers…they should not be accessible to everyone. Apply an ACL that limits communications to only the application servers that need that data (IP addresses and ports).

If you decide to implement network segmentation, take your time! This is a complex undertaking…and if done incorrectly can break things very quickly!

Hope this helps you in your security planning! And have a great week!