Once your event logs are collected and normalized by SEKOIA.IO, you probably want to leverage them to detect suspicious activity within your perimeter. Rules contain the detection logic that determines when Alerts should be created.
All rules are applied to your event stream in real-time, so that you can detect - and respond to - threats as fast as possible.
SEKOIA.IO supports the following rule types:
- Sigma: signature rules using the Sigma detection language
- CTI: rules based on Indicators Of Compromise (IOCs) coming from a Threat Intelligence feed. These rules automatically detect thousands of known malicious indicators (such as domain names, URLs, IP addresses, etc.). A CTI rule "SEKOIA Intelligence Feed" is already built-in to detect malicious activity based on a list of indicators from SEKOIA.IO's own Intelligence feed, continuously updated by our Threat & Detection Research team
- Anomaly: univariate anomaly detection rules.
- STIX (deprecated): signature rules using the STIX Patterning language
The Rules Catalog page can be used to list and manage all detection rules. Many filters are available and can be combined to easily find the rules you are looking for.
You can enable or disable rules one by one or all at once according to current filters.
Available and verified rules
The Rules Catalog lists all detection rules available to your organization:
- Verified Rules: rules with the following logo are verified. These rules are created for you by SEKOIA.IO's Threat & Detection Research team and already built-in. Verified rules are constantly updated to improve detection. Furthermore, they follow a specific process to test them and be certain they won't cause many false positives. This process is described in our blogpost XDR detection engineering at scale: crafting detection rules for SecOps efficiency. This set of more than 550 rules can be used to detect known threats, attack patterns, etc.
- Your Rules: rules created by your team that are specific to your organization.
The Available Rules counter displays the total number of rules (verified + custom). You can click on the
Verified counter to list only Verified rules.
You can then click on the
Verified filter if you would rather see only Custom rules.
All rules have an associated effort level. The effort level is increasing from Elementary to Master according to two criteria:
- Effort needed to enable a rule.
- Risk of false positives.
Elementaryrules require almost no effort and raise fewer alerts
Masterrules are generic and raise a lot of alerts that will require qualification, but they can detect weaker signals. Those rules require an additional customisation effort, which has to be adapted to the customer context You can click on each counter associated with an effort level to see only the rules for this level
The rules are also associated with different capabilities:
- Offensive Capabilities:
attack patternsthat they can detect
- Defensive Capabilities:
data sourceson which they operate
Capabilities that have associated rules inside the catalog are listed on the left of the page. You can click on any Threat, Attack Pattern, or Datasource to list only rules that are associated with it.
To have a filtered view of your rules, you can rely on filters cited before (Available/Verified, Effort level, Capabilities) but also on tags associated with rules.
These tags are defined by SEKOIA.IO analysts to help make searching for a rule easier and provide categories such as
To filter rules using tags, there are two ways:
- Select a tag under a rule and it will filter all rules to show only those with the same tag
- Use the select
Filter by tagnext to the search bar and choose a category from the list
To remove filters, simply click on
Clear all filters next to the tags' list or deselect one tag at a time by clicking on the close icon inside the tag.
Security Profile (MITRE ATT&CK)
The MITRE ATT&CK framework is a comprehensive matrix of tactics and techniques used by threat hunters and defenders to better classify attacks and assess an organization's risk.
Every time you enable a rule, it appears in blue on the matrix in one or many cells. Each cell represents an attack technique. The cells are clickable and enable you to see or disable the rules activated in each one.
You can see how many rules are enabled in a cell by hovering over it.
The color changes depending on the number of rules activated in one cell:
Blue cells means rules are enabled. Darker cells mean there are multiple rules enabled for this technique and lighter cells mean there are only few rules enabled for this tactic.
A white cell means that no rules are activated in it.
You can click on the name of a rule to display additional details, such as, but not limited to:
- The severity which should be used to later determine the Alert's Urgency
- The category of created alerts
- Associated Threats
- Associated Data Sources
- Known False Positives
- The actual detection logic (the pattern)
- Similarity strategy for the produced alerts
Enable new rules
New verified rules are created regularly. You may not want to look at the rules catalog daily to decide if you want to enable them or not. By clicking on the
configure icon at the top right of the Rules Catalog page, you can configure which rules should be automatically enabled for your organization.
Rules are automatically enabled based on the configured effort level, or you can decide to never automatically enable rules.
To ensure that activated rules comply with your security policy, you can choose which rules you want to enable. For an MSSP Community, you can easily enable your custom and verified rules in multiple managed communities.
Create custom rules
In addition to the verified rules that are already built-in, you can create your own rules to support other detection use cases. To create a rule, click on the
+ Rule button at the top right of the page and fill out the form.
The Rule creation form has the following sections:
General definition of the rule
- The rule name is mandatory during the creation, it will be used to name the corresponding raised alerts by default. You can add an optional description below.
- Select the effort level required and the threats detected with this rule if any, by selecting it from the MITRE ATT&CK or by using the search bar through keywords or the drop-down list.
- For an MSSP community, first select the community you want to create your rule in.
- Two options are available: select
All communitiesor select a specific community.
If you choose
All communities, your rule will be available for all your communities and you can enable it later on the desired community.
This is the detection logic itself. It varies according to the selected rule type.
Fields available to create a detection pattern follow the ECS standard and can be found on Events page > Show fields and top values.
In the Alert properties part, you should indicate the category and type of the alerts raised by the rule and the severity of the rule, which is used to calculate the urgency of the corresponding raised alerts in association with assets criticality for events matching assets.
Fields displayed in alert events
You can select fields that will be displayed in events present inside your raised alerts to speed up alert qualification.
To search for fields you want to display, click on the select and type in your event field. This field works as an auto-complete.
Custom similarity strategy
Alerts are considered similar when some event fields have identical values.
You can select these event fields in your rule configuration. To do so, click on the select and type in your event field. You can select as many fields as needed.
In addition to that, these event fields can be added to the
Swappable fields. A typical example of that is
You can learn more about similarity strategies in this section.
Edit your custom rules
When the Rule Details panel is open, you can click on the
Configure icon at the top right to edit the rule's configuration.
For Custom rule, you will be able to edit its main definition:
- General definition of the rule
- Detection Pattern
- Security alerts (event fields can be selected to define the similarity strategy in the section
For an MSSP communty, when you edit this part and your rule is multi-communities, changes will be shared with all your managed communities.
Limiting the scope of a rule
For all types of rules, You will be able to limit its applicable scope with the following filters. For an MSSP community, these filters will be applied only on the community selected:
- Alert Filters: are additional patterns that you can add to any rule to exclude matching events. This is useful to exclude known false positives so that your detections are always spot on. It is often easier to create Alert Filters directly from an Alert.
- Entities: select the entities this rule should apply to. By default, rules apply to all entities.
- Assets: select the assets this rule should apply to. By default, rules apply to all assets
When rules have limited scope with selected entities or assets, these rules will not automatically apply to new entities or assets that are later created.
Notify on new rules
We continuously update the rules catalog with new rules.
To keep posted, we introduced a dedicated trigger in the Notification Center. This new notification trigger enables the creation of notification rules that triggers when a new detection rule is added to the Rules Catalog by SEKOIA.IO.
This trigger supports additionnal filters on the name of the detection rule, its description, pattern or severity.