350-201 Exam Dumps : Performing CyberOps Using Core Security Technologies (CBRCOR)

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.

 The “permission denied” error during script execution indicates that the script does not have execute permissions. The chmod +x ex.sh command changes the script’s permissions to make it executable. This is the necessary step to resolve the permission issue and allow the script to run

The recommended action to mitigate an attack that is broadcasting a large number of ICMP packets using a spoofed source IP address is to use the subinterface command no ip directed-broadcast. This command prevents the Cisco IOS device from forwarding packets that are addressed to IP broadcast addresses. By disabling the directed broadcast feature, the network devices will not respond to broadcast messages sent to the network’s broadcast address, thus mitigating the attack and preventing the amplification of the ICMP packets back to the victim’s IP address.