Investigate Threat Alerts

This page provides details about how to investigate the threat alerts that Cloud IDS generates.

Review alert details

You can review the following JSON fields in the alert log:

  • threat_id - Unique Palo Alto Networks threat identifier.
  • name - Threat name.
  • alert_severity - Severity of the threat. One of INFORMATIONAL, LOW, MEDIUM, HIGH, or CRITICAL.
  • type - Type of the threat.
  • category - Sub-type of the threat.
  • alert_time - Time when the threat was discovered.
  • network - Customer network in which the threat was discovered.
  • source_ip_address - Suspected traffic's source IP address. When you use a Google Cloud load balancer, the true client IP address is not available, and this address is the IP address of your load balancer.
  • destination_ip_address - Suspected traffic's destination IP address.
  • source_port - Suspected traffic's source port.
  • destination_port - Suspected traffic's destination port.
  • ip_protocol - Suspected traffic's IP protocol.
  • application - Suspected traffic's application type—for example, SSH.
  • direction - Suspected traffic's direction (client-to-server or server-to-client).
  • session_id - An internal numerical identifier applied to each session.
  • repeat_count - Number of sessions with the same source IP, destination IP, application, and type seen within 5 seconds.
  • uri_or_filename - URI or filename of the relevant threat, if applicable.
  • cves - a list of CVEs associated with the threat
  • details - Additional information about the type of threat, taken from Palo Alto Networks' ThreatVault.

Search the Palo Alto Networks Threat Vault

Use the following instructions to search for Common Vulnerabilities and Exposures (CVEs), threat IDs, threat names, and threat categories.

  1. If you don't already have an account, create an account on Palo Alto Networks' LiveCommunity.

  2. Access the Palo Alto Networks Threat Vault using your account.

  3. In the Threat Vault, search for any of the following values based on information from your threat alert:

    • One or more CVE from the cves field
    • THREAT_ID from the threat_id field
    • THREAT_NAME from the name field
    • CATEGORY from the category field
  4. Verify that the signature status says Released and not Disabled.

    1. If Disabled, the signature is no longer valid and is disabled. When Cloud IDS catches up on updates from Palo Alto Networks, the signature stops generating alerts.
  5. If a file triggered the finding, perform the following steps:

    1. Search for the hashes that are associated with the signature on the VirusTotal website to determine whether any of them are malicious.
    2. If the hash of the file triggering the signature is known, compare it to those in Threat Vault. If they don't match it's a signature collision, which means that the file and the malicious sample might contain the same byte values in the same byte offsets. If they do match and the file isn't malicious, it's a false positive and you can disregard the threat alert..
  6. If a command-and-control or DNS threat triggered the finding, perform the following steps:

    1. Identify the destination domain that triggered the signature on outbound communications from an endpoint.
    2. Investigate the reputation of domains and IP addresses involved to develop a broad understanding of the potential threat level.
  7. If the traffic has a business impact and you are convinced that the traffic isn't malicious, or if you are willing to accept the risk, you can add Threat Exceptions to your Cloud IDS endpoint to disable the threat ID, .

  8. Implement a Google Cloud Armor rule or a Cloud NGFW rule to block the malicious traffic using the connection source and destination IP addresses in the finding.