Did you know that you can configure Security Onion to only record PCAP for Suricata NIDS alerts?

Folks sometimes ask how to only record PCAP for Suricata NIDS alerts so that they can save disk space. Our preference is to NOT limit PCAP to alerts only since disk is cheap and most sophisticated adversaries are going to try to evade IDS alerts anyway. However, for folks that really need the space savings, here is how you would do it.

First, check to see whether you are using Stenographer or Suricata for PCAP. If you are using Stenographer, you will need to switch to Suricata as shown here (please note the warning):

https://docs.securityonion.net/en/2.4/suricata.html#pcap

Once you're running Suricata for PCAP, you would then set conditional PCAP to "alerts" as shown here:

https://docs.securityonion.net/en/2.4/suricata.html#conditional-pcap

Quick Malware Analysis: GULOADER and REMCOS RAT pcap from 2024-08-26

Thanks to Brad Duncan for sharing this pcap from 2024-08-26 on his malware traffic analysis site! Due to issues with Google flagging a warning for the site, we're not including the actual hyperlink but it should be easy to find.

We did a quick analysis of this pcap on the NEW Security Onion 2.4.100:

https://blog.securityonion.net/2024/08/security-onion-24100-now-available.html

If you'd like to follow along, you can do the following:

• install Security Onion 2.4.100 in a VM:
  https://docs.securityonion.net/en/2.4/first-time-users.html
• import the pcap using the SOC Grid interface:
  https://docs.securityonion.net/en/2.4/grid.html#icons-in-lower-left-corner
• optionally enable the DNS lookups feature:
  https://docs.securityonion.net/en/2.4/soc-customization.html?#reverse-dns-lookups

The screenshots at the bottom of this post show some of the interesting alerts, metadata logs, and session transcripts. Want more practice? Check out our other Quick Malware Analysis posts at:

https://blog.securityonion.net/search/label/quick%20malware%20analysis

About Security Onion

Security Onion is a versatile and scalable platform that can run on small virtual machines and can also scale up to the opposite end of the hardware spectrum to take advantage of extremely powerful server-class machines.  Security Onion can also scale horizontally, growing from a standalone single-machine deployment to a full distributed deployment with tens or hundreds of machines as dictated by your enterprise visibility needs. To learn more about Security Onion, please see:
https://securityonion.net

Screenshots

First, we start with the overview of all alerts and logs:

Next, let's look at just the alerts:

Notice that all of the Remcos alerts are for the same TCP stream:

Let's pivot to see that entire TCP stream:

Now let's switch to ASCII transcript where we see the victim PC sending information to the attacker:

Next, let's look at the Zeek protocol metadata:

We'll start with the HTTP dashboard where we see a request that does a GeoPlugin lookup (related to the GeoPlugin information in a previous screenshot):

Next, we look at the Files dashboard where we see the GeoPlugin response via HTTP:

Next, let's review the SSL/TLS dashboard:

We'll next review the corresponding X509 dashboard:

Here is the DNS dashboard:

Finally, let's review the Connections dashboard:

Here we can see all of the connections that we've seen above and one that we haven't looked at previously (source port 50646):

If we pivot to PCAP on source port 50646, then we see the transfer of a packed EXE:

Near the end of that TCP stream we see usernames and passwords being exfiltrated:

Security Onion Documentation printed book now updated for Security Onion 2.4.100!

We've been offering our Security Onion documentation in book form on Amazon for a few years and it's now been updated for the recently released Security Onion 2.4.100!

Thanks to Richard Bejtlich for writing the inspiring foreword!

Proceeds go to the Rural Technology Fund!

This edition has been updated for Security Onion 2.4.100 and includes a 20% discount code for our on-demand training and certification!

This book covers the following Security Onion topics:

• First Time Users
• Getting Started
• Security Onion Console (SOC)
• Security Onion Desktop
• Network Visibility
• Additional Network Visibility
• Host Visibility
• Third Party Integrations
• Rules
• Logs
• Updating
• Accounts
• Services
• Customizing for Your Environment
• Tricks and Tips
• Utilities
• Help

Q&A

What is the difference between this book and the online documentation?

This book is the online documentation formatted specifically for print. It also includes an inspiring foreword by Richard Bejtlich that is not available anywhere else! Proceeds go to the Rural Technology Fund! Finally, the printed book includes a 20% discount code for our on-demand training and certification.

Who should get this book?

You should get this book if you work on airgap networks or simply want a portable reference that doesn't require an Internet connection or batteries! Also anyone who wants to donate to a worthy cause like Rural Technology Fund!

What is the difference between this edition and the previous edition?

This edition has been updated for Security Onion 2.4.100!

Where do we get it?

https://securityonion.com/book

Security Onion 2.4.100 Hotfix 20240903 now available!

Last week's 2.4.100 release contained an issue that affects deployments that use Kibana dashboards AND have deployed remote agents to endpoints. Today, we are releasing a hotfix which resolves this issue:

https://docs.securityonion.net/en/2.4/release-notes.html

If you have already updated to 2.4.100 and Kibana is not showing source IP addresses correctly, then you should update to this hotfix using soup:

https://docs.securityonion.net/en/2.4/soup.html

After updating to the hotfix, you may still have indices with incorrect data. If so, you can delete the incorrect indices via the command line as follows.

First, become root:

sudo -i

Next, roll over each of the affected data streams:

for i in logs-system.application-default logs-system.security-default logs-system.system-default; do 

    so-elasticsearch-query $i/_rollover -XPOST

done

Then, delete the previous index for each of the affected data streams:

for i in logs-system.application-default logs-system.security-default logs-system.system-default; do

    INDEX_TO_DELETE=$(so-elasticsearch-query $i | jq -r 'keys[]' | tail -2 | head -1); so-elasticsearch-query $INDEX_TO_DELETE -XDELETE

done

Finally, navigate to Kibana -> Security Onion - Home -> Network dashboard to confirm that source IP addresses now display as expected.

New Installations

If this is your first time installing Security Onion 2.4, then we highly recommend starting with an IMPORT installation as shown at:

https://docs.securityonion.net/en/2.4/first-time-users.html

Once you’re comfortable with your IMPORT installation, then you can move on to more advanced installations as shown at:

https://docs.securityonion.net/en/2.4/architecture.html

Documentation

You can find our online documentation here:

https://docs.securityonion.net/en/2.4/

Documentation is always a work in progress. If you find documentation that needs to be updated, please let us know as described in the Feedback section below.

Questions, Problems, and Feedback

If you have any questions or problems relating to Security Onion 2.4, please use the 2.4 category at our Discussions site:

https://github.com/Security-Onion-Solutions/securityonion/discussions/categories/2-4

Security Onion Pro

We recently celebrated 10 years in business by announcing Security Onion Pro:

https://blog.securityonion.net/2024/07/celebrating-10-years-of-security-onion.html

Security Onion Pro includes many enterprise features that folks have been asking for:

• Open ID Connect (OIDC)
• Data at Rest Encryption
• FIPS for the OS
• DoD STIG for the OS
• External Notifications in SOC (this feature got even better in this release!)
• Time Tracking inside of Cases
• Guaranteed Message Delivery

You can read more about these enterprise features at:

https://securityonion.com/pro

Training

Need training? Start with our free Security Onion Essentials training and then take a look at some of our other official Security Onion training!

https://securityonion.net/training

Security Onion Solutions Hardware Appliances

We know Security Onion's hardware needs, and our appliances are the perfect match for the platform. Leave the hardware research, testing, and support to us, so you can focus on what's important for your organization. Not only will you have confidence that your Security Onion deployment is running on the best-suited hardware, you will also be supporting future development and maintenance of the Security Onion project!

https://securityonionsolutions.com/hardware