Creating a Forensics and Response Rule
The AlienApp for Forensics and Response allows you to create orchestration rules that automatically run a data collection or enforcement action in response to future events or alarms that meet your criteria. You can define the rule to run the action on the associated source asset, associated destination asset, or any asset you specify.
All rules include a rule name and conditional expression. They can also include optional multiple occurrence and window length parameters. There are two methods for creating a new AlienApp for Forensics and Response orchestration rule in USM Anywhere.
From an Applied Action — You can automatically create a rule using the action that you apply from an existing alarm or event. This makes it easy to set the matching conditions for the rule based on the existing item and use the same settings that you applied to that item.
In the confirmation dialog, click Create rule for similar alarms or Create rule for similar events.
From the Rules page: The Rules page provides access to all of your orchestration rules. The Orchestration Rules list includes suppression rules, alarm rules, filtering rules, notification rules, and response action rules. You can create new rules using the specific matching conditions that you define, as well as edit, delete, and enable/disable rules. For more information about managing orchestration rules, see Orchestration Rules.
Go to Settings > Rules and select Response Action Rules on the left navigation panel. Then click Create Response Action Rule to define the new rule.
Both of these methods display the Create Response Action Rule dialog. Use this dialog to specify the new rule, including the Forensics and Response action to run and the criteria for a future event or alarm that triggers the rule.
To define a Forensics and Response rule
- Enter a unique Rule Name.
Select the Action for the rule.
Review the information in Supported Actions to determine the action that you want to use for the rule.
Choose the target Asset for the action.
- Source Asset — Use this option to use the source endpoint of the alarm or event as the target asset.
- Destination Asset — Use this option to use the destination endpoint of the alarm or event as the target asset.
- Select another Asset — Use this option to specify the asset that is always the target for the action when the rule is triggered. Use the search text box or click Browse Assets to locate and select the asset.
At the bottom of the dialog box, set the Rule Condition parameters to specify the criteria for a matching alarm or event to trigger the rule.
- If you create the rule from an applied action, this section provides suggested property/value pairs from the selected alarm or event that you can use as conditions for the rule. Click the icon to delete the items that you do not want to include in the matching conditions. You can also add other conditions that are not suggested.
- If you create the rule from the Rules page, you must use the Add Condition and Add Group functions to define the property/value pairs that you want to use as conditions for the rule.
Click the More link at the bottom of the dialog box to display the optional multiple occurrence and window length parameters.Conditional Expression
Choose an operator and add one or more conditions to form the conditional expression. You can include a condition group to evaluate a subset of conditions. The Current Rule box displays the constructed expression in standard syntax. The box displays a red border if the expression is syntactically invalid as currently specified. A valid expression is required to save the rule definition.
Select the operator used to determine the match for multiple conditions.
- Select AND to match all conditions.
- Select OR to match any one condition.
- Select AND NOT to exclude items matching all conditions after the first.
- Select OR NOT to include all items that do not match any conditions after the first.
Click Add Condition to add a condition. For each condition, specify the field name, evaluator, and value. If the evaluation returns true for the condition, it is a match.
Click Add Group to add a condition group. A new group includes a condition and its own operator used to match the conditions within the group. You can nest condition groups.Occurrences
Specify the number of event or alarm occurrences that produce a match on the conditional expression to trigger the rule. The default value is 1. You can enter the number of occurrences or use the arrow to scroll the value up or down.
USM Anywhere uses this in conjunction with the Length option to specify the number of occurrences within a time period that will trigger the rule. For example, you can define a rule to trigger for an unauthorized access attempt when a failed SSHProgram to securely log into another computer over a network, to execute commands in a remote machine, and to move files from one machine to another through SCP. login occurs three times within a five minute window.Length
Specify the length of the window to identify a match for multiple occurrences. Enter the number and choose a time unit value of seconds, minutes, or hours. This time period identifies the amount of time that transpires from the first occurrence to the last occurrence. If the number of occurrences is not met within this period, the rule does not trigger.
- Click Save Rule.
- Click OK in the confirmation dialog.