An intelligent DNS sinkhole is a system used by security teams to fight, block, and collect information about adversaries infiltrated the organization. It is also used by security researchers to collect information about botnets activities and the adversaries’ PPTs.
Most common to security professionals are DNS sinkholes[1]. This provides the prevention of malicious and unwanted activity occurring between organization computers system and the Internet. This blog focuses on how deception technology can serve as an intelligent DNS sinkhole.
Deception technology can assist in collecting information about the adversaries’ goals of already infected assets inside the organization and how they tried to reach those goals.
Deception collects vital intel on attackers
Organizations use Threat Intelligence to block the communication of attackers that infiltrated the organization with Command and Control (C&C) servers on the Internet. Such blocking can be done using a FW, IPS, and other security gateways based on TI. Blocking prevents the operations of the adversaries when they try to connect with C&C or when they try to access assets that they should not be accessing. However, by “just” blocking the attackers, the defenders cannot learn about the adversaries’ goals, PPTs, etc. For example, what protocols the attackers are using, what they are looking for, which tools they use, etc. Using deception, the defenders can gather all this information and more. This approach also helps in identifying and mitigating threats posed by malicious software, thereby enhancing the overall security posture of the organization.
The method of using deception as an intelligent DNS sinkhole
Using deception technology as an intelligent sinkhole relies on rerouting suspicious DNS queries and unidentified DNS traffic to a Decoy Server. This process often involves resolving these queries to a controlled IP address, which leads to a intelligent DNS sinkhole, thereby preventing users from connecting to dangerous domains. This can be done through the organization’s DNS server, the FW or the IPS. The DNS traffic that will be directed to the Decoy Server might include any ports or protocols the adversary is using to carry the attacks or to connect with the C&C server. The Decoy Server itself is configured to have relevant ports open and, with applications running on these ports, capable of interacting with the adversary. It should include HTTP(S) application, FTP application, database servers, DNS server and more. A Concurrently local services like shared folders and RDP should be configured.
Turn the tables on cybercriminals:
- Lure attackers into traps
- Detect breaches faster
- Gather intel for smarter defenses
DNS Decoy for intercepting DNS queries
When a DNS (domain name service) is used to redirect the adversaries’ traffic to the decoy server, the DNS decoy should be configured on the Decoy Server. The organization’s DNS server should then forward the DNS request to the decoy DNS server, which is responsible for intercepting DNS queries and returning the IP addresses of the decoys. You can have multiple decoys running on multiple IP addresses. Each can run multiple services and the decoy DNS can round robin among these decoy servers. Security teams also have the option to use the decoys as part of their incident response strategy. You can feed attackers with false information leading them in the wrong direction.
When an attacker interacts with one of the decoys, the interactions can progress for quite a while. For example, when the attacker connects to an FTP server, he goes through the login process, then traverses the file system of the decoy, and writes or reads a file.
Forensic information collected in the Sinkhole Server with a controlled IP address
Deception technology can collect all the activities of the attacker with the decoy system. It can then present it in a graphical manner, allowing the security team to inspect all activities. At the same time, a PCAP file for these activities can be captured. If the deception solution is integrated with other systems that are inspecting traffic (e.g., Network Detection & Response), then the entire traffic of the infected asset can be captured in a PCAP file. This allows the security team to analyze malicious traffic and gain insights into the behavior and techniques used by the attackers.
Note that when Fidelis Deception is integrated with EDR tool, the decoy can inform the EDR about the activities taking place with the decoy. Then, the EDR can start tracing the process and the activities of the adversary communicating with the decoy.
Expanding Intelligent Sinkhole Capabilities with Deception Technology
DNS sinkholes have long been a cornerstone of network security, providing organizations with a powerful method to redirect malicious traffic away from its intended destination. By enhancing traditional DNS sinkholes with deception technology, security teams can transform this defensive tool into an latest threat intelligence-gathering powerhouse, creating truly intelligent DNS sinkholes that not only block threats but reveal valuable insights about attackers’ methods and objectives.
The Evolution of DNS Sinkholes in Modern Security
DNS sinkholes work by intercepting DNS queries to known harmful domains and redirecting them to a controlled IP address instead of their intended destination. This redirection of DNS traffic effectively prevents communication with command and control servers, data exfiltration attempts, and other malicious activities. While traditional DNS sinkholes focus primarily on blocking, intelligent DNS sinkholes take this concept further by actively engaging with attackers to collect threat intelligence.
When suspicious traffic is detected attempting to reach malicious sites, the intelligent DNS sinkhole doesn’t just block the connection—it creates an opportunity to study the attack. By forwarding DNS requests to a deception environment, security teams can observe how attackers operate when they believe they’ve successfully connected to their target. This provides invaluable information about attack patterns, tools, and techniques that can be used to strengthen overall security posture.
Implementing an Intelligent DNS Sinkhole Architecture
To build an effective intelligent DNS sinkhole, organizations need to configure their DNS server to work in conjunction with deception technology. DNS servers store databases that contain mappings for domain names to their respective IP addresses. The process begins when the DNS server identifies queries to known malicious domains or suspicious DNS queries that match patterns of malicious activity. Instead of simply blocking these requests, the DNS server redirects them to a decoy environment.
This architecture requires several components:
- A primary DNS server configured to identify and redirect malicious DNS queries
- A decoy DNS server capable of intercepting DNS queries and providing responses that lead to the deception environment
- Decoy systems with a controlled IP address that simulate real services and applications
- Monitoring tools to capture and analyze the malicious traffic and attacker behavior
The decoy environment should be configured to mimic your organization’s actual infrastructure, making it difficult for attackers to distinguish between legitimate systems and the deception environment. This includes implementing common services like HTTP, HTTPS, FTP, and database servers that respond realistically to attacker interactions.
Collecting and Analyzing Threat Intelligence
One of the most significant advantages of an intelligent DNS sinkhole is its ability to gather detailed threat intelligence. When malicious software attempts to communicate with its command and control server, the DNS sinkhole not only prevents this communication but also captures information about:
- The specific malicious domains being accessed
- The types of DNS requests being made
- The protocols and ports being used
- The actions attempted by the attacker
- The malicious traffic patterns that might indicate specific attack types
This intelligence allows security teams to understand not just that an attack occurred, but exactly how it operated and what it was attempting to accomplish. By analyzing this data, organizations can develop more effective defenses against similar attacks in the future.
Real-World Applications and Benefits
Organizations implementing intelligent DNS sinkholes have reported significant improvements in their security posture. For example, one financial institution was able to identify and neutralize a previously undetected persistent threat by analyzing the traffic patterns captured by their intelligent DNS sinkhole. The attacker had been attempting to exfiltrate data via DNS tunneling—a technique that might have gone unnoticed without the detailed visibility provided by the deception environment.
Beyond just blocking known malicious domains, intelligent DNS sinkholes excel at detecting and analyzing:
- Zero-day exploits attempting to communicate with new command and control servers
- Lateral movement attempts within the network
- Data exfiltration techniques that use DNS as a covert channel
- Malware beaconing patterns and frequencies
Future Directions in DNS Sinkhole Technology
As threats continue to evolve, so too must our defensive capabilities. The next generation of intelligent DNS sinkholes is incorporating machine learning to identify suspicious traffic patterns without relying solely on lists of known malicious domains. These systems can detect anomalies in DNS queries that might indicate new attack techniques or previously unknown malicious domains.
By combining these advanced detection capabilities with the intelligence-gathering power of deception technology, organizations can create a powerful defensive system that not only protects against current threats but helps anticipate and prepare for future attacks so your network can’t be compromised.
Discover More with Fidelis Deception
To learn more about how you can implement an intelligent DNS sinkhole using deception technology, explore Fidelis Deception’s comprehensive solution. Fidelis Deception provides organizations with the tools needed to create convincing decoys, monitor attacker behavior, and gather actionable threat intelligence that can strengthen your overall security strategy. Our experts can help you design and implement a deception-based intelligent DNS sinkhole tailored to your organization’s specific needs and infrastructure.
Combine deception with DNS sinkholes to:
- Divert attackers to controlled decoys
- Monitor their tactics, techniques, and procedures
- Gain actionable threat intelligence — instantly
Frequently Ask Questions
What is DNS Sinkholing?
DNS sinkholing is a security technique that redirects malicious DNS queries to a controlled IP address, often referred to as a “sinkhole.
How do intelligent DNS sinkholes minimize false positives?
Intelligent DNS sinkholes use reputation scoring and behavioral analysis to accurately distinguish between legitimate and malicious DNS traffic. By whitelisting trusted domain names and implementing custom rules based on normal traffic patterns, these systems effectively reduce false positives while ensuring legitimate business operations continue uninterrupted.
Can intelligent DNS sinkholes protect against subdomain attacks?
Yes. These systems analyze entire DNS request patterns, not just root domain names. This enables detection of malicious activity hidden within subdomains of legitimate domains. When suspicious subdomain activity is identified, only that specific traffic is redirected to the deception environment, protecting your network while maintaining normal operations.
Citations:
