Refer to the exhibits.

Understanding the Threat Hunting Data :

The Threat Hunting Monitor in the provided exhibits shows various application services, their usage counts, and data metrics such as sent bytes, average sent bytes, and maximum sent bytes.

The second part of the exhibit lists connection attempts from a specific source IP (10.0.1.10) to a destination IP (8.8.8.8), with repeated " Connection Failed " messages.

Analyzing the Application Services :

DNS is the top application service with a significantly high count (251,400) and notable sent bytes (9.1 MB).

This large volume of DNS traffic is unusual for regular DNS queries and can indicate the presence of DNS tunneling.

DNS Tunneling :

DNS tunneling is a technique used by attackers to bypass security controls by encoding data within DNS queries and responses. This allows them to extract data from the local network without detection.

The high volume of DNS traffic, combined with the detailed metrics, suggests that DNS tunneling might be in use.

Connection Failures to 8.8.8.8 :

The repeated connection attempts from the source IP (10.0.1.10) to the destination IP (8.8.8.8) with connection failures can indicate an attempt to communicate with an external server.

Google DNS (8.8.8.8) is often used for DNS tunneling due to its reliability and global reach.

Conclusion :

Given the significant DNS traffic and the nature of the connection attempts, it is reasonable to conclude that DNS tunneling is being used to extract confidential data from the local network.

Why Other Options are Less Likely :

Spearphishing (A) : There is no evidence from the provided data that points to spearphishing attempts, such as email logs or phishing indicators.

Reconnaissance (C) : The data does not indicate typical reconnaissance activities, such as scanning or probing mail servers.

FTP C & C (D) : There is no evidence of FTP traffic or command-and-control communications using FTP in the provided data.