Copy_Configuring Security Insights

During the installation of Security Insights or after it's up and running, there are a few things you can do to customize the application for your domain.

Tune alert priorities

Each of the security alerts has been assigned a default priority. While our security experts have carefully considered the priorities for each alert, you can customize the priorities if you choose.

The valid priority values are:

To do so, you’ll need to edit the AlertDescriptionLocal.csv lookup file or upload it if it doesn't yet exist in the Devo domain where Security Insights is installed. Simply add one line for each alert for which you want to change the priority. Although there are other fields, to change the priority of an existing alert you only need to specify the alertName and the priority values in this file.

Once you have edited and saved this file, follow the instructions for uploading a lookup table. Be sure to set the data type for alertCategory and priority to integer and the rest to alphanumeric.

If the lookup file already exists, follow the instructions for editing an uploaded lookup. If the alert already appears in the existing lookup, you only need to edit the priority value. If it doesn’t appear in the lookup, add a new row where you enter the alertName and the new priority.

Create custom security alerts

Define the alert

While our security alerts address a wide range of security events, you can create your own alerts to meet the specific needs of your environment.

First, create the new alert as you would with any other alert with just two additional requirements:

• The Alert Name must start with SecInt. For example, SecIntMyCustomAlert.

• The Subcategory must be threats.

• Optionally, if you want to use your custom alert to create an alert chain, you must include the fields you want to use to join it with the rest of alerts of the chain in the Message. Add them at the end of the message, preceded by ||. For example:
  IP $sourceIP is creating connections to multiple IP addresses in the last 5 minutes//sourceIP;destIP

The fields added to use as joins for an alert chain must be named in a specific way in order to match the names of the fields in the default alerts defined by Devo. 

This table lists the names accepted by Devo for the following default alert fields:

In the query below, we have changed the names of two fields (srcPort and dstPort) and given them one of the accepted names:

Add the alert to Security Insights

Now you need to add the alert to Security Insights by including it in the AlertDescriptionLocal lookup file.

• If this lookup already exists, simply edit the lookup and add a new line for the alert. To see the list of lookups, go to Data Search and open the Lookup Management tab.

• If it doesn’t exist, you can download our template and enter the values that describe your new alert. Then when you’ve saved the CSV file containing your new alert, upload it to your Devo domain:

• It is important to set the correct field types when uploading the template as a lookup file. Devo is able to identify the template as a CSV file and separate the fields properly, but you must change the default value Integer number to Alphanumeric, as shown in the picture:

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Here’s an example of a hypothetical custom alert called SecIntMyCustomAlert. The 6 fields you can see in the template file are mandatory to set. Priority and alertCategory are integer, the rest are alphanumeric. In alertFields you need to set the fields you added to the grouping to make them appear in the Security Insights user interface.

The possible values for the alertCategory field are:

Create an alert chain

You can combine two or more of the alerts defined for the application to create an alert chain. An alert chain combines the criteria of multiple selected alerts. An alert chain is triggered when its component alerts all meet the established criteria. The queries that define the alerts in the chain are joined using a common field; that is to say, a field that is present in all of them. For example, you might create an alert chain to notify you when the same source IP address has triggered two separate alert types within a specified period of time.

To create an alert chain:

1. Click the lightning icon in the top right. 
   
   
   

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2. You will see a list of all the alerts that are defined for the application. Select New alert chain to start the process.

3. In step 1, you select the alerts you want to combine. Use the search to find specific alerts by the contents of their name or description. Click Next step when you're done.
   
   
   

4. In step 2, you set the join field, time window, alert chain details.

These are the fields to complete:

Click Next step when you're done. Step 3 is simply a summary of the alert chain. Review and confirm the alert chain definition. You can select Show query to check the definition of the alert. Click Create alert to confirm the alert chain and create it.

Close the dialog and open it again to see the newly defined alert chain. You can create a new alert chain using this newly alert—there is no limitation in creating new alert chains using other alert chains or common alerts.

Now you can go to Administration → Alerts Configuration and locate the new alert chain. Alert chains are automatically activated after you create them. However, note that they can be disabled, but not edited nor deleted. Following versions of the Security Insights application will make these options available. 

Learn more about alerts and how to configure them reading the articles in the Configuring alerts section.

Create an IP address white list

You might have a list of IP addresses that generate activity on your network but that you know for sure do not pose threats. In this case, you can create a white list so that any alerts generated by events involving these IPs as the Source ID are immediately disregarded.

To implement the white list, we create a post-processing filter in the Alerts area of the web application. These filters must be created from a triggered alert that appears in your Alert Dashboard, and will affect all the occurrences of that alert definition.

For instance, we have an alert that detects port scan attacks (SecIntTestPortScan) and we want to discard the alerts that are triggered by two specific IPs: 77.72.85.17 and 188.22.33.44. These two IP addresses are causing a lot of noise and belong to internal servers so we want to discard them.

We must filter out these IPs and add them to a white list as Watched. To do it, we must click one instance of this alert in the Alert Dashboard and select New Filter.

When defining the filter:

• Add conditions only in the Extra Data field, not in Basic Data (only for Devo predefined alerts).

• Select srcIpStr under Extra Data and set it to the IP address you want on the white list (in this case 77.72.85.17). Click the + icon to add it. Note that you can set only one condition per filter.

• Once the condition is added, select the Action to be applied when the condition fits. We will select Mark as read to watch the alerts meeting the condition as Watched. Click Save to end the process.

In the window that appears, click Add to enter the second IP to the filter (188.22.33.44). Repeat the steps above and click Save again.

Once saved, the filter will set to Watched all the triggered alerts where the Source IP is one of the IPs specified in the filter. In the following image, you can see the effect of the sample filters. Two SecIntTestPortScan alerts are automatically set to Watched in the Alerts Dashboard because the IP matches with the filter. The other alert has a different IP so it is triggered normally.

You can apply other filters as required and the status of the alert will be updated in the Alert Dashboard and in the siem.logtrust.alert.info table. If you select the Delete action, the alert will obviously not appear.

Each action has a different status code that you can check in the status column of the siem.logtrust.alert.info table. In the following example, we have changed the alert state from New (code 4) to False Positive (code 2). 

To modify the white list, it’s necessary to create a new filter with the updated list of Source IP addresses, then delete the existing filter. Post-filters cannot be edited.

Disable unused tabs (or re-enable them)

By default, the application contains nine different tabs; Overview, Threats, Network, DNS, Firewall, Proxy, Access, Web and IDS but Admin users can disable (or hide) any tabs that are not currently used in their deployment. For example, if your domain doesn’t have IDS data sources, it makes sense to disable the IDS tab.

To do this, we again use a special lookup file called Tabs.csv. This file has just two fields; tab is set to the tab name and enabled is set to either true or false (in lowercase):

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Simply set a tab to false to hide it in the application. You can edit your lookup at any time to enable or disable tabs. Download the template that you can modify, then follow the instructions to upload it to your domain.