This error now occurs in the log due to a change in the exception handling within Salts event module. You may want to bump the SID into the 90,000,000 range and set the revision to 1. Revision 39f7be52. Open /etc/nsm/rules/local.rules using your favorite text editor. Security Onion is a free and open platform for threat hunting, enterprise security monitoring, and log management. Next, run so-yara-update to pull down the rules. There are multiple ways to handle overly productive signatures and well try to cover as many as we can without producing a full novel on the subject. To unsubscribe from this group and stop receiving emails from it, send an email to. Inside of /opt/so/saltstack/local/salt/strelka/rules/localrules, add your YARA rules. Where is it that you cannot view them? More information on each of these topics can be found in this section. (Archived 1/22) Tuning NIDS Rules in Security Onion Security Onion 7.5K subscribers 48 Dislike Share 1,465 views Dec 22, 2021 This video has been archived as of January 2022 - the latest. The server is also responsible for ruleset management. Please keep this value below 90 seconds otherwise systemd will reach timeout and terminate the service. Start by creating Berkeley Packet Filters (BPFs) to ignore any traffic that you don't want your network sensors to process. Another consideration is whether or not the traffic is being generated by a misconfigured piece of equipment. This section will cover both network firewalls outside of Security Onion and the host-based firewall built into Security Onion. In a distributed Security Onion environment, you only need to change the configuration in the manager pillar and then all other nodes will get the updated rules automatically. . The second only needs the $ character escaped to prevent bash from treating that as a variable. After adding your rules, update the configuration by running so-strelka-restart on all nodes running Strelka. Security Onion generates a lot of valuable information for you the second you plug it into a TAP or SPAN port. Security Onion a free and open platform for intrusion detection, enterprise security monitoring, and log management. For example, consider the following rules that reference the ET.MSSQL flowbit. Between Zeek logs, alert data from Suricata, and full packet capture from Stenographer, you have enough information to begin identifying areas of interest and making positive changes to your security stance. Copyright 2023 /opt/so/saltstack/local/salt/idstools/local.rules, "GPL ATTACK_RESPONSE id check returned root 2", /opt/so/saltstack/local/salt/strelka/rules, /opt/so/saltstack/local/salt/strelka/rules/localrules, /opt/so/saltstack/local/salt/strelka/rules/, https://github.com/Neo23x0/signature-base. From https://docs.saltstack.com/en/latest/: Salt is a core component of Security Onion 2 as it manages all processes on all nodes. 7.2. Edit the /opt/so/rules/nids/local.rules file using vi or your favorite text editor: sudo vi /opt/so/rules/nids/local.rules Paste the rule. When editing these files, please be very careful to respect YAML syntax, especially whitespace. /opt/so/saltstack/default/salt/firewall/assigned_hostgroups.map.yaml is where the default allow rules come together and pair hostgroups and portgroups and assign that pairing to a node based on its role in the grid. In Security Onion, locally created rules are stored in /opt/so/rules/nids/local.rules. This writeup contains a listing of important Security Onion files and directories. Adding Your Own Rules . Previously, in the case of an exception, the code would just pass. Revision 39f7be52. Apply the firewall state to the node, or wait for the highstate to run for the changes to happen automatically. Finally, run so-strelka-restart to allow Strelka to pull in the new rules. A. Revision 39f7be52. I've just updated the documentation to be clearer. After adding your rules, update the configuration by running so-strelka-restart on all nodes running Strelka. Then tune your IDS rulesets. Though each engine uses its own severity level system, Security Onion converts that to a standardized alert severity: event.severity: 4 ==> event.severity_label: critical, event.severity: 3 ==> event.severity_label: high, event.severity: 2 ==> event.severity_label: medium, event.severity: 1 ==> event.severity_label: low. To configure syslog for Security Onion: Stop the Security Onion service. The default allow rules for each node are defined by its role (manager, searchnode, sensor, heavynode, etc) in the grid. Saltstack states are used to ensure the state of objects on a minion. This will add the IPs to the host group in, Since we reused the syslog port group that is already defined, we dont need to create a new port group. For example, to check disk space on all nodes: If you want to force a node to do a full update of all salt states, you can run so-checkin. 3. If this is a distributed deployment, edit local.rules on your master server and it will replicate to your sensors. If you have Internet access and want to have so-yara-update pull YARA rules from a remote Github repo, copy /opt/so/saltstack/local/salt/strelka/rules/, and modify repos.txt to include the repo URL (one per line). Start by creating Berkeley Packet Filters (BPFs) to ignore any traffic that you dont want your network sensors to process. Alternatively, run salt -G 'role:so-sensor' cmd.run "so-strelka-restart" to restart Strelka on all sensors at once. We created and maintain Security Onion, so we know it better than anybody else. When configuring network firewalls for Internet-connected deployments (non-Airgap), youll want to ensure that the deployment can connect outbound to the following: In the case of a distributed deployment, you can configure your nodes to pull everything from the manager so that only the manager requires Internet access. 41 - Network Segmentation, VLANs, and Subnets. 2. Logs. That's what we'll discuss in this section. Beta If you pivot from that alert to the corresponding pcap you can verify the payload we sent. =========================================================================Top 50 All time Sguil Events=========================================================================Totals GenID:SigID Signature1686 1:1000003 UDP Testing Rule646 1:1000001 ICMP Testing Rule2 1:2019512 ET POLICY Possible IP Check api.ipify.org1 1:2100498 GPL ATTACK_RESPONSE id check returned rootTotal2335, =========================================================================Last update=========================================================================. The files in this directory should not be modified as they could possibly be overwritten during a soup update in the event we update those files. However, the exception is now logged. Our instructors are the only Security Onion Certified Instructors in the world and our course material is the only authorized training material for Security Onion. Security Onion Peel Back the Layers of Your Enterprise Monday, January 26, 2009 Integrating Snort 3.0 (SnortSP) and Sguil in 3 Steps So once you have Snort 3.0 installed, what can you do with it? 2GB RAM will provide decent performance for the Sguil client and retrieving packet captures from the server but also enough to run Security Onion in standalone mode for monitoring the local client and testing packet captures with tools like tcpreplay, Revision 39f7be52. . Write your rule, see Rules Format and save it. To enable the Talos Subscriber ruleset in an already installed grid, modify the /opt/so/saltstack/local/pillar/minions/ file as follows: To add other remotely-accessible rulesets, add an entry under urls for the ruleset URL in /opt/so/saltstack/local/pillar/minions/: Copyright 2023 To generate traffic we are going to use the python library scapy to craft packets with specific information to ensure we trigger the alert with the information we want: Craft the layer 2 information. If you are on a large network, you may need to do additional tuning like pinning processes to CPU cores. One of those regular interventions is to ensure that you are tuning properly and proactively attempting to reach an acceptable level of signal to noise. When you run so-allow or so-firewall, it modifies this file to include the IP provided in the proper hostgroup. There isnt much in here other than anywhere, dockernet, localhost and self. The error can be ignored as it is not an indication of any issue with the minions. Enter the following sample in a line at a time. These non-manager nodes are referred to as salt minions. In order to apply the threshold to all nodes, place the pillar in /opt/so/saltstack/local/pillar/global.sls. /opt/so/saltstack/default/salt/firewall/hostgroups.yaml is where the default hostgroups are defined. Adding local rules in Security Onion is a rather straightforward process. The county seat is in Evansville. Security Onion is an open-source and free Linux distribution for log management, enterprise security monitoring, and intrusion detection. Cleaning up local_rules.xml backup files older than 30 days. While Vanderburgh County was the seventh-largest county in 2010 population with 179,703 people, it is also the eighth-smallest county in area in Indiana and the smallest in southwestern Indiana, covering only 236 square miles (610 km2). /opt/so/saltstack/default/salt/firewall/portgroups.yaml is where the default port groups are defined. By default, only the analyst hostgroup is allowed access to the nginx ports. Its important to note that with this functionality, care should be given to the suppressions being written to make sure they do not suppress legitimate alerts. Please note! It's simple enough to run in small environments without many issues and allows advanced users to deploy distributed systems that can be used in network enterprise type environments. Once logs are generated by network sniffing processes or endpoints, where do they go? Modifying these values outside of so-allow or so-firewall could lead to problems accessing your existing hosts. Our documentation has moved to https://securityonion.net/docs/. Of course, the target IP address will most likely be different in your environment: destination d_tcp { tcp("192.168.3.136" port(514)); }; log { For example: By default, if you use so-allow to add a host to the syslog hostgroup, that host will only be allowed to connect to the manager node. Backing up current local_rules.xml file. ELSA? Launch your Ubuntu Server VM, log on with credentials provided at the beginning of this guide and open a terminal shell by double-clicking the Desktop shortcut. Let's add a simple rule that will alert on the detection of a string in a tcp session: Run rule-update (this will merge local.rules into downloaded.rules, update sid-msg.map, and restart processes as necessary): If you built the rule correctly, then Snort/Suricata should be back up and running. Security Onion has Snort built in and therefore runs in the same instance. Here, we will show you how to add the local rule and then use the python library scapy to trigger the alert. To add local YARA rules, create a directory in /opt/so/saltstack/local/salt/strelka/rules, for example localrules. In this file, the idstools section has a modify sub-section where you can add your modifications. For example, if you want to modify SID 2009582 and change $EXTERNAL_NET to $HOME_NET: The first string is a regex pattern, while the second is just a raw value. Once your rules and alerts are under control, then check to see if you have packet loss. After select all interfaces also ICMP logs not showing in sguil. Default pillar file: This is the pillar file located under /opt/so/saltstack/default/pillar/. PFA local.rules. Salt minions must be able to connect to the manager node on ports, /opt/so/saltstack/local/pillar/global.sls, /opt/so/saltstack/local/pillar/minions/.sls, https://docs.saltproject.io/en/getstarted/system/communication.html, https://docs.saltproject.io/en/latest/topics/troubleshooting/yaml_idiosyncrasies.html. Naming convention: The collection of server processes has a server name separate from the hostname of the box. You may see the following error in the salt-master log located at /opt/so/log/salt/master: The root cause of this error is a state trying to run on a minion when another state is already running. You can find the latest version of this page at: https://securityonion.net/docs/AddingLocalRules. You can do so via the command line using curl: Alternatively, you could also test for additional hits with a utility called tmNIDS, running the tool in interactive mode: If everything is working correctly, you should see a corresponding alert (GPL ATTACK_RESPONSE id check returned root) in Alerts, Dashboards, Hunt, or Kibana. Adding local rules in Security Onion is a rather straightforward process. On Thursday, June 15, 2017 at 5:06:51 PM UTC+5:30, Wes wrote: Is it simply not triggering, or causing an error? > > => I do not know how to do your guilde line. At those times, it can be useful to query the database from the commandline. Security Onion Solutions, LLC is the creator and maintainer of Security Onion, a free and open platform for threat hunting, network security monitoring, and log management. You should only run the rules necessary for your environment, so you may want to disable entire categories of rules that dont apply to you. lawson cedars. Introduction Adding local rules in Security Onion is a rather straightforward process. ET Open optimized for Suricata, but available for Snort as well free For more information, see: https://rules.emergingthreats.net/open/ ET Pro (Proofpoint) optimized for Suricata, but available for Snort as well rules retrievable as released Please note if you are using a ruleset that enables an IPS policy in /etc/nsm/pulledpork/pulledpork.conf, your local rules will be disabled. 1. Before You Begin. You may want to bump the SID into the 90,000,000 range and set the revision to 1. Here, we will show you how to add the local rule and then use the python library scapy to trigger the alert. This repository has been archived by the owner on Apr 16, 2021. These policy types can be found in /etc/nsm/rules/downloaded.rules. Security Onion offers the following choices for rulesets to be used by Snort/Suricata: ET Open optimized for Suricata, but available for Snort as well free For more information, see: https://rules.emergingthreats.net/open/ ET Pro (Proofpoint) optimized for Suricata, but available for Snort as well rules retrievable as released Pillars are a Saltstack concept, formatted typically in YAML, that can be used to parameterize states via templating. Security Onion. We can start by listing any rules that are currently modified: Lets first check the syntax for the add option: Now that we understand the syntax, lets add our modification: Once the command completes, we can verify that our modification has been added: Finally, we can check the modified rule in /opt/so/rules/nids/all.rules: To include an escaped $ character in the regex pattern youll need to make sure its properly escaped. Network Security Monitoring, as a practice, is not a solution you can plug into your network, make sure you see blinking lights and tell people you are secure. It requires active intervention from an analyst to qualify the quantity of information presented. For example, if ips_policy was set to security, you would add the following to each rule: The whole rule would then look something like: alert tcp any any -> $HOME_NET 7789 (msg: "Vote for Security Onion Toolsmith Tool of 2011! However, generating custom traffic to test the alert can sometimes be a challenge. Reboot into your new Security Onion installation and login using the username/password you specified in the previous step. Any definitions made here will override anything defined in other pillar files, including global. If you need to manually update your rules, you can run the following on your manager node: If you have a distributed deployment and you update the rules on your manager node, then those rules will automatically replicate from the manager node to your sensors within 15 minutes. If you try to disable the first two rules without disabling the third rule (which has flowbits:isset,ET.MSSQL) the third rule could never fire due to one of the first two rules needing to fire first. This can be done in the minion pillar file if you want the delay for just that minion, or it can be done in the global.sls file if it should be applied to all minions. . Add the following to the minions sls file located at. To enable the ET Pro ruleset in an already installed grid, modify the /opt/so/saltstack/local/pillar/minions/ file as follows: Since Shared Object rules wont work with Suricata, you may want to disable them using a regex like 're:soid [0-9]+' as described in the Managing Alerts section. For example, if you dont care that users are accessing Facebook, then you can silence the policy-based signatures for Facebook access. Minion pillar file: This is the minion specific pillar file that contains pillar definitions for that node. A new version of our securityonion-rule-update package is now available that distributes OSSEC's local_rules.xml from master server to slave sensors by default and also allows for NIDS/HIDS rule tuning per physical sensor. The format of the pillar file can be seen below, as well as in /opt/so/saltstack/default/pillar/thresholding/pillar.usage and /opt/so/saltstack/default/pillar/thresholding/pillar.example. The signature id (SID) must be unique. Security Onion uses idstools to download new signatures every night and process them against a set list of user generated configurations. /opt/so/saltstack/local/salt/firewall/assigned_hostgroups.local.map.yaml is where host group and port group associations would be made to create custom host group and port group assignements that would apply to all nodes of a certain role type in the grid. Salt is a new approach to infrastructure management built on a dynamic communication bus. Some of these refer to areas where data is stored, while others point to configuration files that can be modified to change how Security Onion interacts with various tools. Default YARA rules are provided from Florian Roths signature-base Github repo at https://github.com/Neo23x0/signature-base. You signed in with another tab or window. Security Onion includes best-of-breed free and open tools including Suricata, Zeek, Wazuh, the Elastic Stack and many others. For example, if you had a web server you could include 80 and 443 tcp into an alias or in this case a port group. Within 15 minutes, Salt should then copy those rules into /opt/so/rules/nids/local.rules. Our appliances will save you and your team time and resources, allowing you to focus on keeping your organization secure.