To create a security policy that will automatically add infected hosts to the infected hosts feed and block further communication through the SRX Series device, you need to add a security intelligence policy to the permit portion of the security policy. A security intelligence policy is a policy that allows you to block or monitor traffic from malicious sources based on threat intelligence feeds from Juniper ATP Cloud or other providers. One of the feeds that you can use is the Infected-Hosts feed, which contains IP addresses of hosts that are infected with malware and communicate with command-and-control servers. You can create a profile and a rule for the Infected-Hosts feed and specify the threat level and the action to take for the infected hosts. Then, you can link the security intelligence policy with the firewall policy and apply it to the traffic that you want to protect.

You have exceeded the maximum files submission for your SRX platform size: This statement is correct because file scanning on SRX300 Series device has a limit on the number of files that can be submitted per minute based on the platform size3. For example, SRX320 has a limit of 10 files per minute3.

Reference:
The Intrusion Prevention System (IPS) is a feature that provides protection against network-based threats. The IPS uses a rule base to evaluate network traffic and apply actions based on the rules that match the traffic.
When evaluating the rule base, the IPS evaluates the rules concurrently (option A). This means that the IPS can apply multiple rules to the same traffic simultaneously.
If multiple rules match the same traffic, the IPS applies the most severe action (option B). This means that if there are conflicting actions specified in different rules, the IPS will apply the action that has the highest severity. For example, if one rule specifies a "drop" action and another rule specifies a "log" action for the same traffic, the IPS will drop the traffic because dropping has a higher severity than logging.

The configuration shown in the exhibit is for a Juniper SRX Series firewall. The session-init parameter is used to control how the firewall processes unknown traffic flows. With the session- init parameter set to 300, any traffic flows that the firewall does not recognize will be dropped after 300 milliseconds. Additionally, every session that enters the device, whether it is known or unknown, will generate an event, which can be used for logging and troubleshooting purposes.
The session-lose parameter is used to control how the firewall handles established sessions that are terminated.