{"id":90406,"date":"2020-08-01T01:41:57","date_gmt":"2020-07-31T23:41:57","guid":{"rendered":"https:\/\/prohoster.info\/blog\/administrirovanie\/chto-takoe-dns-tunnelirovanie-instrukcziya-po-obnaruzheniyu"},"modified":"2020-08-01T01:41:57","modified_gmt":"2020-07-31T23:41:57","slug":"chto-takoe-dns-tunnelirovanie-instrukcziya-po-obnaruzheniyu","status":"publish","type":"post","link":"https:\/\/prohoster.info\/en\/blog\/administrirovanie\/chto-takoe-dns-tunnelirovanie-instrukcziya-po-obnaruzheniyu","title":{"rendered":"What is DNS tunneling? A guide to detection.","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

\"What
\n
\nDNS tunneling turns the domain name system into a weapon for hackers. DNS is essentially a vast phone book of the internet. Moreover, DNS is a fundamental protocol that allows administrators to query the DNS server's database. So far, everything seems clear. But crafty hackers realized they could secretly communicate with the victim's computer by embedding control commands and data into the DNS protocol. This idea lies at the core of DNS tunneling.
\n<\/a><\/noindex><\/p>\n

How DNS Tunneling Works<\/h2>\n

\n\"What
\n
\nEvery service on the internet has its own distinct protocol. DNS supports a relatively simple the protocol <\/a><\/noindex>request-response type. If you want to see how it works, you can run nslookup \u2013 the main tool for sending DNS queries. You can request an address simply by specifying the desired domain name, for example:<\/p>\n

\"What
\n
\nIn our case, the protocol responded with the IP address of the domain. In DNS protocol terms, I made an address query or an 'A' type query. There are other types of queries, and the DNS protocol will respond with different sets of data fields that, as we will see later, hackers can exploit.<\/p>\n

In any case, at its core, the DNS protocol handles the transmission of a request to the server and its response back to the client. But what if an attacker embeds a covert message inside the domain name request? For instance, instead of entering a perfectly legitimate URL, they input the data they want to transmit:<\/p>\n

\"What
\n
\nSuppose the attacker controls a DNS server. Then they can transmit data \u2013 such as personal information \u2013 and may not necessarily be detected. After all, why would a DNS request suddenly become something illegitimate? <\/p>\n

By controlling the server, hackers can spoof responses and send data back to the target system. This allows them to transmit messages hidden in various fields of the DNS response to malicious software on the infected machine, with instructions such as searching within a specific folder.<\/p>\n

The 'tunneling' part of this attack lies in hiding <\/a><\/noindex> data and commands from detection by monitoring systems. Hackers can use character sets like base32, base64, etc., or even encrypt data. Such encoding will pass unnoticed by simple threat detection tools that search for plain text.<\/p>\n

And this is DNS tunneling!<\/p>\n

The History of DNS Tunneling Attacks<\/h2>\n

\nEverything has a beginning, including the idea of hijacking the DNS protocol for hacker purposes. As far as we can tell, the first sparked <\/a><\/noindex>such attack was conducted by Oskar Pearson in a Bugtraq mailing list in April 1998.<\/p>\n

By 2004, DNS tunneling was presented at Black Hat as a hacking method in Dan Kaminsky's presentation. Thus, the idea quickly evolved into a real attack tool.<\/p>\n

Today, DNS tunneling occupies a solid position on the map of potential threats <\/a><\/noindex>(and information security bloggers are often asked to explain it).<\/p>\n

Have you heard about Sea Turtle <\/a><\/noindex>? \u042d\u0442\u043e \u0434\u0435\u0439\u0441\u0442\u0432\u0443\u044e\u0449\u0430\u044f \u043a\u0430\u043c\u043f\u0430\u043d\u0438\u044f \u043a\u0438\u0431\u0435\u0440\u043f\u0440\u0435\u0441\u0442\u0443\u043f\u043d\u044b\u0445 \u0433\u0440\u0443\u043f\u043f\u0438\u0440\u043e\u0432\u043e\u043a \u2014 \u0441\u043a\u043e\u0440\u0435\u0435 \u0432\u0441\u0435\u0433\u043e, \u0441\u043f\u043e\u043d\u0441\u0438\u0440\u0443\u0435\u043c\u0430\u044f \u0433\u043e\u0441\u0443\u0434\u0430\u0440\u0441\u0442\u0432\u043e\u043c, \u2014 \u043d\u0430\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u043d\u0430\u044f \u043d\u0430 \u0437\u0430\u0445\u0432\u0430\u0442 \u043b\u0435\u0433\u0438\u0442\u0438\u043c\u043d\u044b\u0445 DNS-\u0441\u0435\u0440\u0432\u0435\u0440\u043e\u0432 \u0441 \u0446\u0435\u043b\u044c\u044e \u043f\u0435\u0440\u0435\u043d\u0430\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u044f DNS-\u0437\u0430\u043f\u0440\u043e\u0441\u043e\u0432 \u043d\u0430 \u0441\u043e\u0431\u0441\u0442\u0432\u0435\u043d\u043d\u044b\u0435 \u0441\u0435\u0440\u0432\u0435\u0440\u0430. \u042d\u0442\u043e \u043e\u0437\u043d\u0430\u0447\u0430\u0435\u0442, \u0447\u0442\u043e \u043e\u0440\u0433\u0430\u043d\u0438\u0437\u0430\u0446\u0438\u0438 \u0431\u0443\u0434\u0443\u0442 \u043f\u043e\u043b\u0443\u0447\u0430\u0442\u044c \u00ab\u043f\u043b\u043e\u0445\u0438\u0435\u00bb IP-\u0430\u0434\u0440\u0435\u0441\u0430, \u0443\u043a\u0430\u0437\u044b\u0432\u0430\u044e\u0449\u0438\u0435 \u043d\u0430 \u043f\u043e\u0434\u0434\u0435\u043b\u044c\u043d\u044b\u0435 \u0432\u0435\u0431-\u0441\u0442\u0440\u0430\u043d\u0438\u0446\u044b \u043f\u043e\u0434 \u0443\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435\u043c \u0445\u0430\u043a\u0435\u0440\u043e\u0432, \u2014 \u043d\u0430\u043f\u0440\u0438\u043c\u0435\u0440, Google \u0438\u043b\u0438 FedEx. \u041f\u0440\u0438 \u044d\u0442\u043e\u043c \u0437\u043b\u043e\u0443\u043c\u044b\u0448\u043b\u0435\u043d\u043d\u0438\u043a\u0438 \u0441\u043c\u043e\u0433\u0443\u0442 \u0437\u0430\u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u0443\u0447\u0451\u0442\u043d\u044b\u0435 \u0437\u0430\u043f\u0438\u0441\u0438 \u0438 \u043f\u0430\u0440\u043e\u043b\u0438 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u0435\u0439, \u043a\u043e\u0442\u043e\u0440\u044b\u0435 \u0442\u0435 \u043d\u0435\u043e\u0441\u043e\u0437\u043d\u0430\u043d\u043d\u043e \u0432\u0432\u0435\u0434\u0443\u0442 \u0438\u0445 \u043d\u0430 \u0442\u0430\u043a\u0438\u0445 \u043f\u043e\u0434\u0434\u0435\u043b\u044c\u043d\u044b\u0445 \u0441\u0430\u0439\u0442\u0430\u0445. \u042d\u0442\u043e \u043d\u0435 DNS-\u0442\u0443\u043d\u043d\u0435\u043b\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u0435, \u043d\u043e \u043f\u0440\u043e\u0441\u0442\u043e \u0435\u0449\u0451 \u043e\u0434\u043d\u043e \u0441\u043a\u0432\u0435\u0440\u043d\u043e\u0435 \u043f\u043e\u0441\u043b\u0435\u0434\u0441\u0442\u0432\u0438\u0435 \u043a\u043e\u043d\u0442\u0440\u043e\u043b\u044f DNS-\u0441\u0435\u0440\u0432\u0435\u0440\u043e\u0432 \u0445\u0430\u043a\u0435\u0440\u0430\u043c\u0438.<\/p>\n

The Threats of DNS Tunneling<\/h2>\n

\n\"What
\n
\nDNS tunneling acts as an indicator of the onset of bad news. What kind? We have already mentioned a few, but let's structure them:<\/p>\n