How can DNS tunneling be prevented?
Staying vigilant for suspicious domains, monitoring DNS traffic, and reporting suspicious domains to threat intelligence platforms, can help reduce the effectiveness of DNS tunnels in abetting malicious C2 activity.
What does DNS tunneling do?
DNS tunneling exploits the DNS protocol to tunnel malware and other data through a client-server model. A connection is now established between the victim and the attacker through the DNS resolver. This tunnel can be used to exfiltrate data or for other malicious purposes.
What are signs of DNS tunneling?
Some indicators of DNS tunneling on a network can include:
- Unusual Domain Requests: DNS tunneling malware encodes data within a requested domain name (like DATA_HERE.baddomain.com).
- Requests for Unusual Domains: DNS tunneling only works if the attacker owns the target domain so that DNS requests go to their DNS server.
What is DNS Tunnelling and how can it be detected?
DNS tunnels can be detected by analyzing a single DNS payload or by traffic analysis such as analyzing count and frequency of requests. Payload analysis is used to detect malicious activity based on a single request.
How do I secure my DNS?
Here are some of the most effective ways to lock down DNS servers.
- Use DNS forwarders.
- Use caching-only DNS servers.
- Use DNS advertisers.
- Use DNS resolvers.
- Protect DNS from cache pollution.
- Enable DDNS for secure connections only.
- Disable zone transfers.
- Use firewalls to control DNS access.
What are the best mitigation strategies to minimize what an attacker can obtain from using DNS?
How can I prevent DNS attacks?
- Audit your DNS zones. First things first.
- Keep your DNS servers up-to-date.
- Hide BIND version.
- Restrict Zone Transfers.
- Disable DNS recursion to prevent DNS poisoning attacks.
- Use isolated DNS servers.
- Use a DDOS mitigation provider.
- Two-Factor Authentication.
What is listening on port 53?
Description: “DNS” is the glue that translates human-readable domain and machine names like “grc.com” or “amazon.com” into their machine-readable Internet Protocol (IP) address equivalents. DNS servers listen on port 53 for queries from DNS clients.
How to protect your network from DNS tunneling?
Protecting against DNS tunneling requires an advanced network threat prevention system capable of detecting and blocking this attempted data exfiltration.
What does it mean when a domain is tunneling?
If an organization is experiencing a sudden surge in requests for an unusual domain, it may indicate DNS tunneling, especially if that domain was only created recently. High DNS Traffic Volume: The domain name within a DNS request has a maximum size (253 characters).
Why do hackers use port 53 for DNS tunneling?
In particular, hackers are exploiting DNS as a pathway for data exfiltration. That’s right — someone could be siphoning valuable or sensitive information from your network through DNS. The use of DNS, specifically port 53, for data theft is often called DNS tunneling.
Can a spike in DNS traffic be a sign of tunneling?
The resulting spike in DNS traffic can be an indicator of DNS tunneling. All of these factors can be benign on their own. However, if an organization is experiencing several or all of these abnormalities, it may be an indication that DNS tunneling malware is present and active within the network.