https://www.cisco.com/c/en/us/td/docs/security/esa/esa120/user_guide/b_ESA_Admin_Guide_12_0/b_ESA_Admin_Guide_chapter_01100.html

Cisco Umbrella Investigate is a cloud-based service that provides interactive threat intelligence on domains, IPs, and files. It helps security analysts to uncover the attacker's infrastructure and predict future threats by analyzing the relationships and evolution of internet domains, IPs, and files. It also integrates with other Cisco security solutions, such as Cisco Secure Network Analytics, Cisco Secure Cloud Analytics, and Cisco pxGrid, to provide a holistic view of the network and cloud security posture. Cisco Umbrella Investigate is based on the data collected by Cisco Umbrella, which processes more than 620 billion DNS requests per day from over
190 countries. Cisco Umbrella Investigate uses statistical and machine learning models to automatically score and classify the data, and provides a risk score for each domain, IP, and file, along with the contributing factors and historical context. Cisco Umbrella Investigate also allows security analysts to query the data using a web-based console or an API, and to visualize the results using graphs, tables, and maps. Cisco Umbrella Investigate is the most complete and interactive threat intelligence solution that helps to prevent cyber attacks before they happen. References := Some possible references are:
* Cisco Umbrella Investigate
* Cyber Attack Prevention - Cisco Umbrella
* Cisco Umbrella Investigate - Cisco Umbrella

ICMP is a protocol that is used to send diagnostic messages between hosts on a network. It is not designed to carry any data, but it can be abused by attackers to exfiltrate data from a compromised host. By encrypting the payload in an ICMP packet, the attacker can hide the data from network monitoring tools and firewalls that may not inspect ICMP traffic. The attacker can then use another tool to decrypt the data from the ICMP packets on a remote host. This technique is known as ICMP tunneling and it is a form of protocol tunneling (MITRE T1572: Protocol Tunneling1). References:
* 1: https://attack.mitre.org/techniques/T1572/
* 2: https://www.cynet.com/attack-techniques-hands-on/how-hackers-use-icmp-tunneling-to-own-your- network/
* 3: https://digital-security.quodagis.fr/ressources/ressource/exfiltration-de-donnees-les-techniques-icmp- et-dns-tunneling-855

DNS tunneling is a technique that uses the DNS protocol to exfiltrate data or establish command and control channels between a compromised host and an attacker-controlled server. DNS tunneling can bypass network security controls that allow outbound DNS traffic without inspection or filtering. To stop DNS tunneling, two recommended approaches are:
* Enforce security over port 53. This means applying firewall rules, access control lists, or other mechanisms to restrict outbound DNS traffic to only authorized DNS servers and domains. Additionally, DNS traffic should be inspected and analyzed for anomalies, such as unusually large or frequent queries, non-standard encoding, or suspicious domains. This can help detect and block DNS tunneling attempts.
* Use Cisco Umbrella. Cisco Umbrella is a cloud-based security service that provides DNS security, web
* filtering, and threat intelligence. Cisco Umbrella can prevent DNS tunneling by blocking malicious domains, enforcing policies based on content categories, and applying machine learning to identify and stop emerging threats. Cisco Umbrella can also provide visibility and reporting on DNS activity and security events.
References :=
* Implementing and Operating Cisco Security Core Technologies (SCOR) v1.0, Module 5: Securing the Cloud, Lesson 5.2: DNS Security
* What Is DNS Tunneling? - Palo Alto Networks
* An Introduction to DNS Tunneling Detection & Data Exfiltration via DNS - Vercara