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Cisco Defense Orchestrator

Working with Alerts Based on Firepower Threat Defense Events

Working with Alerts Based on Firepower Threat Defense Events

Required License: Firewall Analytics and Monitoring or Total Network Analytics and Monitoring

Alerts Workflow

An alert's workflow is based around its status. When the system generates an alert, the default status is Open, and no user is assigned. When you view the Alerts summary, all open alerts are displayed by default, as these are of immediate concern.

Note: If you have a Total Network Analytics and Monitoring license, your alerts can be based on observations generated from NetFlow, observations generated from Firepower Threat Defense (FTD) events, or observations from both data sources.

As you review the Alerts summary, you can assign, tag, and update status on alerts as an initial triage. You can use the filters and search functionality to locate specific alerts, or display alerts of different statuses, or associated with different tags or assignees.

You can set an alert's status to Snoozed, in which case it does not reappear in the list of open alerts until the snooze period elapses. You can also remove Snoozed status from an alert, to display it as an open alert again. As you review alerts, you can assign them to yourself or another user in the system. Users can search for all alerts assigned to their username.

From the Alerts summary, you can view an alert detail page. This page allows you to review additional context about the supporting observations that resulted in this alert, and additional context about the entities involved in this alert. This information can help you pinpoint the actual issue, in order to further research the issue on your network, and potentially resolve malicious behavior.

As you research within the Stealthwatch Cloud web portal UI, in CDO, and on your network, you can leave comments with the alert that describe your findings. This helps create a record for your research that you can reference in the future.

If you complete your analysis, you can update the status to Closed, and have it no longer appear by default as an open alert. You can also re-open a closed alert in the future if circumstances change.

The following presents general guidelines and suggestions for how to investigate a given alert. Because Stealthwatch Cloud provides additional context when it logs an alert, you can use this context to help guide your investigation.

These steps are meant to be neither comprehensive, nor all-inclusive. They merely offer a general framework with which to start investigating an alert.

In general, you can take the following steps when you review an alert:

Triage open alerts

Triage the open alerts, especially if more than one have yet to be investigated:

Ask the following questions:

  • Have you configured this alert type as high priority?
  • Did you set a high sensitivity for the affected subnet?
  • Is this unusual behavior from a new entity on your network?
  • What is the entity's normal role, and how does the behavior in this alert fit that role?
  • Is this an exceptional deviation from normal behavior for this entity?
  • If a user is involved, is this expected behavior from the user, or exceptional?
  • Is protected or sensitive data at risk of being compromised?
  • How severe is the impact to your network if this behavior is allowed to continue?
  • If there is communication with external entities, have these entities established connections with other entities on your network in the past?

If this is a high priority alert, consider quarantining the entity from the internet, or otherwise closing its connections, before continuing your investigation.

Snooze alerts for later analysis

Snooze alerts when they are of lesser priority, as compared to other alerts. For example, if your organization is repurposing an email server as an FTP server, and the system generates an Emergent Profile alert (indicating that an entity's current traffic matches a behavior profile that it did not previously match), you can snooze this alert as it is intended behavior, and revisit it at a later date. A snoozed alert does not show up with the open alerts; you must specifically filter to review these snoozed alerts.

Snooze an alert:

  1. Click Close Alert.
  2. In the Snooze this alert pane, select a snooze period from the drop-down.
  3. Click Save.

When you are ready to review these alerts, you can unsnooze them. This sets the status to Open, and displays the alert alongside the other Open alerts.

Unsnooze a snoozed alert:

  • From a snoozed alert, click Unsnooze Alert.

Update the alert for further investigation

Open the alert detail:

  1. Select Alerts.
  2. Click an alert type name.

Based on your initial triage and prioritization, assign the alert and tag it:

  1. Select a user from the Assignee drop-down to assign the alert, so a user can start investigating.
  2. Select one or more Tags from the drop-down to add tags to the alert, to better categorize your alert's for future identification, as well as to try and establish long-term patterns in your alerts.
  3. Enter a Comment on this alert, then click Comment to leave comments as necessary to track your initial findings, and assist the person assigned to the alert. The alert tracks both system comments and user comments.

Review the alert and start your investigation

If you are reviewing an assigned alert, review the alert detail to understand why Stealthwatch Cloud generated an alert. Review the supporting observations to understand what these observations mean for the source entity.

Note that if the alert was generated based on FTD events, the system does not note that your FTD deployment was the source of this alert.

View all of the supporting observations for this source entity to understand its general behavior and patterns, and see if this activity may be part of a longer trend:

  1. From the alert detail, click the arrow icon () next to an observation type to view all logged observations of that type.
  2. Click the arrow icon () next to All Observations for Network to view all logged observations for this alert's source entity.

Download the supporting observations in a comma-separated value file, if you want to perform additional analysis on these observations:

  • From the alert detail, in the Supporting Observations pane, click CSV.

From the observations, determine if the source entity behavior is indicative of malicious behavior. If the source entity established connections with multiple external entities, determine if the external entities are somehow related, such as if they all have similar geolocation information, or their IP addresses are from the same subnet.

View additional context surrounding the source entity from a source entity IP address or hostname, including other alerts and observations it may be involved in, information about the device itself, and what type of session traffic it is transmitting:

  • Select Alerts from the IP address or hostname drop-down to view all alerts related to the entity.
  • Select Observations from the IP address or hostname drop-down to view all observations related to the entity.
  • Select Device from the IP address or hostname drop-down to view information about the device.
  • Select Session Traffic from the IP address or hostname drop-down to view session traffic related to this entity.
  • Select Copy from the IP address or hostname drop-down to copy the IP address or hostname.

Note that the source entity in Stealthwatch Cloud is always internal to your network. Contrast this with the Initiator IP in an FTD event, which indicates the entity that initiated a connection, and may be internal or external to your network.

From the observations, examine information about other external entities. Examine the geolocation information, and determine if any of the geolocation data or Umbrella data identifies a malicious entity. View the traffic generated by these entities. Check whether Talos, AbuseIPDB, or Google have any information on these entities. Find the IP address on multiple days and see what other types of connections the external entity established with entities on your network. If necessary, locate those internal entities and determine if there is any evidence of compromise or unintended behavior.

Review the context for an external entity IP address or hostname with which the source entity established a connection:

  • Select IP Traffic from the IP address or hostname drop-down to view recent traffic information for this entity.
  • Select Session Traffic from the IP address or hostname drop-down to view recent session traffic information for this entity.
  • Select AbuseIPDB from the IP address or hostname drop-down to view information about this entity on AbuseIPDB's website.
  • Select Cisco Umbrella from the IP address or hostname drop-down to view information about this entity on Cisco Umbrella's website.
  • Select Google Search from the IP address or hostname drop-down to search for this IP address on Google.
  • Select Talos Intelligence from the IP address or hostname drop-down to view information about this information on Talos's website.
  • Select Add IP to watchlist from the IP address or hostname drop-down to add this entity to the watchlist.
  • Select Find IP on multiple days from the IP address or hostname drop-down to search for this entity's traffic from the past month.
  • Select Copy from the IP address or hostname drop-down to copy the IP address or hostname.

Note that connected entities in Stealthwatch Cloud are always external to your network. Contrast this with the Responder IP in an FTD event, which indicates the entity that responded to a connection request, and may be internal or external to your network.

Leave comments as to your findings.

  • From the alert detail, enter a Comment on this alert, then click Comment.

Examine the entity and users

After you review the alert in the Stealthwatch Cloud portal UI, you can perform an additional examination on a source entity directly, any users that may have been involved with this alert, and other related entities.

  • Determine where the source entity is on your network, physically or in the cloud, and access it directly. Locate the log files for this entity. If it is a physical entity on your network, access the device to review the log information, and see if there is any information as to what caused this behavior. If it is a virtual entity, or stored in the cloud, access the logs and search for entries related to this entity. Examine the logs for further information on unauthorized logins, unapproved configuration changes, and the like.
  • Examine the entity. Determine if you can identify malware or a vulnerability on the entity itself. See if there has been some malicious change, including if there are physical changes to a device, such as a USB stick that is not approved by your organization.
  • Determine if a user on your network, or from outside your network, was involved. Ask the user what they were doing if possible. If the user is unavailable, determine if they were supposed to have access, and if a situation occurred that prompted this behavior, such as a terminated employee uploading files to an external server before leaving the company.

Leave comments as to your findings:

  • From the alert detail, enter a Comment on this alert, then click Comment.

Remediate the issue

If malicious behavior caused the alert, remediate the malicious behavior. For example:

  • If a malicious entity or user attempted to log in from outside your network, update your firewall rules and FTD configuration to prevent the entity or user from accessing your network.
  • If an entity attempted to access an unauthorized or malicious domain, examine the affected entity to determine if malware is the cause. If there are malicious DNS redirects, determine if other entities on your network are affected, or part of a botnet. If this is intended by a user, determine if there is a legitimate reason for this, such as testing firewall settings. Update your firewall rules and FTD configuration to prevent further access to the domain.
  • If an entity is exhibiting behavior that is different from the historical entity model behavior, determine if the behavior change is intended. If it is unintended, examine whether an otherwise authorized user on your network is responsible for the change. Update your firewall rules and FTD configuration to address unintended behavior if it involves connections with entities that are external to your network.
  • If you identify a vulnerability or exploit, update or patch the affected entity to remove the vulnerability, or update your FTD configuration to prevent unauthorized access. Determine if other entities on your network may similarly be affected, and apply the same update or patch to those entities. If the vulnerability or exploit currently does not have a fix, contact the appropriate vendor to let them know.
  • If you identify malware, quarantine the entity and remove the malware. Review the FTD file and malware events to determine if other entities on your network are at risk, and quarantine and update the entities to prevent this malware from spreading. Update your security intelligence with information about this malware, or the entities that caused this malware. Update your FTD access control and file and malware rules to prevent this malware from infecting your network in the future. Alert vendors as necessary.
  • If malicious behavior resulted in data exfiltration, determine the nature of the data sent to an unauthorized source. Follow your organization's protocols for unauthorized data exfiltration. Update your FTD configuration to prevent future data exfiltration attempts by this source.

Update and close the alert

Add additional tags based on your findings:

  1. In the SWC portal UI, select Alerts.
  2. Select one or more Tags from the drop-down.

Add final comments describing the results of your investigation, and any remediation steps taken:

  • From an alert's detail, enter a Comment on this alert, then click Comment.

Close the alert, and mark it as helpful or not helpful:

  1. From an alert's detail, click Close Alert.
  2. Select Yes if the alert was helpful, or No if the alert was unhelpful. Note that this does not necessarily mean that the alert resulted from malicious behavior, just that the alert was helpful to your organization.
  3. Click Save.

Reopen a closed alert

If you discover additional information related to a closed alert, or want to add more comments related to that alert, you can reopen it, changing the status to Open. You can then make changes as necessary to the alert, then close it again when your additional investigation is complete.

Reopen a closed alert:

  • From a closed alert's detail, click Reopen Alert.