How do I stop DNS data exfiltration?

03/20/2019 Off By admin

How do I stop DNS data exfiltration?

Three crucial components include: First, perform general monitoring and traffic analysis. Internal host or devices shouldn’t use an external resolver and bypass network security. Secondly, analyze DNS payload and network traffic on a per-client basis. The security needs to be implemented at the resolver level.

What are three methods for preventing data exfiltration?

How to prevent data exfiltration: 8 best practices

  • Block unauthorized communication channels.
  • Prevent phishing attacks.
  • Systematically revoke data access for former employees.
  • Educate employees.
  • Identify and redact sensitive data.
  • Set a clear BYOD policy.
  • Identify malicious and unusual network traffic.

Why was DNS selected as the means to exfiltrate data?

DNS is frequently used as a pathway for data exfiltration, because it is not inspected by common security controls. Infoblox Threat Insight technology can provide protection against the most sophisticated data-exfiltration techniques.

What protocol is used to exfiltrate data?

File Transfer Protocol Exfiltration File transfer protocol (FTP) is a network protocol used for transferring files between a client and a server on a computer network.

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
  • 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 exfiltration techniques?

Exfiltration consists of techniques that adversaries may use to steal data from your network. Once they’ve collected data, adversaries often package it to avoid detection while removing it. This can include compression and encryption.

What are the two most common causes of data loss?

Studies show hardware failure and human error are the two most common causes of data loss, accounting for roughly three quarters of all incidents. Another cause of data loss is a natural disaster, which is a greater risk dependent on where the hardware is located.

Why is port 53 used?

DNS uses Port 53 which is nearly always open on systems, firewalls, and clients to transmit DNS queries. Once a name is resolved to an IP caching also helps: the resolved name-to-IP is typically cached on the local system (and possibly on intermediate DNS servers) for a period of time.

What is DNS data exfiltration?

DNS data exfiltration is a way to exchange data between two computers without any direct connection. Instead of responding with an A record in response, the attacker’s name server will respond back with a CNAME, MX or TXT record, which allows a large amount of unstructured data to be sent between attacker and victim.

How do I stop DNS tunneling?

To avoid the possession of data, a tool must be installed that blacklists the destinations which are to extract data. This activity must be done on a regular basis. A DNS firewall should be configured and designed such that it quickly identifies any intrusion. A firewall serves as a pathway for exfiltration.

What is exfiltration in cyber security?

A common data exfiltration definition is the theft or unauthorized removal or movement of any data from a device. Data exfiltration typically involves a cyber criminal stealing data from personal or corporate devices, such as computers and mobile phones, through various cyberattack methods.

What’s the idea of a DNS exfiltration attack?

So here is the idea of DNS exfiltration attack: Instead of just posting the data out to your servers (firewall blocked), you instead have your code make DNS query. Firewalls don’t normally block that because DNS is super-important to operate for most of the servers.

How to bypass security products via DNS data exfiltration?

Due to several conditions such as well-segmented networks, security products or even the block of outgoing TCP traffic, data exfiltration and malware communications from internal networks or devices is seen as an absolute challenge. DNS protocol abuse can be performed in specific scenarios where no TCP outgoing communication is possible.

Which is the port used for DNS infiltration?

In this report we introduce the types, methods, and usage of DNS-based data infiltration and exfiltration and provide some pointers towards defense mechanisms. DNS uses Port 53 which is nearly always open on systems, firewalls, and clients to transmit DNS queries.

Is there a python script for DNS exfiltration?

This python script is our DNS exfiltration tool which allows us to dump and parse received data. As an alternative, if you don’t want run python, you can just record TCPDUMP logs on your server and open them in Wireshark, then filter DNS packets and analyze.