Which regex matches only on all lowercase letters?

An engineer must configure network systems to detect command-and-control communications by decrypting ingress and egress perimeter traffic and allowing network security devices to detect malicious outbound communications. Which technology must be used to accomplish this task?

Refer to the exhibit.

What is occurring?

Drag and drop the definition from the left onto the phase on the right to classify intrusion events according to the Cyber Kill Chain model.

Refer to the exhibit.
What must be interpreted from this packet capture?