Cisco 350-201 Exam With Confidence Using Practice Dumps

Wireshark decrypts TLS network traffic by using a key log file that contains per-session secrets1. This method is effective even when Diffie-Hellman (DH) key exchange is used, which is common in modern encrypted communications. The key log file is typically generated by applications like web browserswhen the SSLKEYLOGFILE environment variable is set. This file records the necessary per-session secrets that Wireshark can then use to decrypt the traffic1.

It’s important to note that while this method is universal and works across different TLS versions, including TLS 1.3, other methods such as using an RSA private key are limited to certain conditions and do not work with TLS 1.3 or when (EC)DHE cipher suites are selected1. Therefore, the key log file method is the most reliable and widely applicable approach for decrypting TLS in Wireshark.

The packet capture shown in the exhibit is indicative of DNS tunneling. This conclusion is drawn from the observation of the packets’ consistent size and frequency, which are directed to a specific destination IP address. Such a pattern is characteristic of DNS tunneling, where data is encapsulated within DNS queries and responses. This method is often used to bypass security controls or for data exfiltration, as it can blend with regular DNS traffic, making detection more challenging.

DNS tunneling can be used for legitimate purposes, such as when an organization’s remote workers need to access internal networks. However, it is also a technique commonly exploited by attackers to smuggle data out of a network or to communicate with command and control servers while evading detection.

References:

Cisco’s official training materials on Performing CyberOps Using Cisco Security Technologies (CBRCOR) provide insights into analyzing packet captures and identifying different types of network traffic, including malicious activities like DNS tunneling.

The Cisco CyberOps Associate Certification resources include detailed information on threat identification and response strategies pertinent to DNS tunneling.