1. Overview

Prisma Cloud provides runtime protection to ensure that network connections made to and from your containers meet the policy defined by rules and modeling. Response to deviations from the resultant policy can be customized through runtime rules.

Prisma Cloud ships with a rule named Default - alert on suspicious runtime behavior that enables runtime protection for networking by default. You can further refine your policy by creating additional custom rules that target specific resources, enable or disable protection features, and define exceptions to the automatically generated allow-list models.

2. Networking rules

Prisma Cloud can monitor container networking activity for patterns that indicate an attack might be underway. These features can be independently enabled or disabled with runtime rules. The final policy that’s enforced is the sum of the container model and your runtime rules.

New runtime rules can be created in Console in Defend > Runtime > Container Policy. Click Add rule, specify a rule name and scope in the General tab, then select the Networking tab to define how Prisma Cloud handles container networking protection.

For more information on how rules are applied, and how models and rules are combined to create a resultant policy, see the article on runtime defense.

2.1. IP connectivity

When Prisma Cloud detects an outgoing connection that deviates from your runtime policy, Prisma Cloud Defender can take action. Networking rules let you put Defender into one of three modes:

  • Disable — Defender does not provide any networking protection.

  • Alert — Defender raises alerts when targeted resources establish connections that violate your runtime policy. The corresponding audits can be reviewed under Monitor > Events > Container Audits.

  • Block — Defender stops the container if it establishes a connection that violates your runtime policy. The corresponding audit can be reviewed under Monitor > Events > Container Audits.

The fields for Explicitly allowed and Explicitly denied let you tailor the runtime models for known good and known bad network connections. These rules define the policy for listening ports, outbound internet ports for Internet destinations, and outbound IP addresses. Defining network policy through runtime rules lets you specify permitted and forbidden behavior for given resources, and instructs Defender on how to handle traffic that deviates from the resultant policy.

2.2. Detect port scanning

Port scans are used by attackers to find which ports on a network are open and listening. If enabled, Defenders detect network behavior indicative of port scanning. If detected, a port scanning incident is created in Incident Explorer.

2.3. Raw sockets

Prisma Cloud can monitor your environment for raw sockets, which can indicate suspicious activity. Raw sockets let programs manipulate packet headers and implement custom protocols to do things such as port scanning.

Raw socket detection is enabled by default.

2.4. DNS

Modern attacks, particularly coordinated, long running attacks, use short lived DNS names to route traffic from the victim’s environment to command and control systems. This is common in large scale botnets. When DNS monitoring is enabled (Alert, Prevent, or Block) in your runtime rules, Prisma Cloud analyzes DNS lookups from your running containers. By default, DNS monitoring is disabled.

Dangerous domains are detected as follows:

  • Prisma Cloud Intelligence Stream — Prisma Cloud’s threat feed contains a list of known bad domains.

  • Behavioral container models — When learning a model for a container, Prisma Cloud records any DNS resolutions that a container makes. When the model is activated, Defender monitors network traffic for DNS resolutions that deviate from the learned DNS resolutions. Audits from DNS monitoring may be be used to trigger a data exfiltration incident.

    You can see the domains in the model by going to Monitor > Runtime > Container Models, clicking on a model, then opening the Networking tab. Known good domains are listed under Behaviorally learned domains.

  • Explicit allow and deny lists: Runtime rules let you augment the Prisma Cloud’s Intelligence Stream data and models with your own explicit lists of known good and bad domains. Define these lists in your runtime rules.

In your runtime rules, set Effect in the DNS section to configure how Defender handles DNS lookups from containers:

  • Disable: DNS monitoring is disabled. DNS lookups are not modeled in learning mode. DNS lookups aren’t analyzed when models are active.

  • Alert: DNS monitoring is enabled. DNS lookups are modeled in learning mode. DNS lookups are analyzed when models are active. Anomalous activity generates audits.

  • Prevent: DNS monitoring is enabled. DNS lookups are modeled in learning mode. DNS lookups are analyzed when models are active. Anomalous activity generates audits. Anomalous DNS lookups are dropped.

  • Block DNS monitoring is enabled. DNS lookups are modeled in learning mode. DNS lookups are analyzed when models are active. Anomalous activity generates audits. When anomalous DNS lookups are detected, the entire container is stopped.