Explanation
DNS tunneling may be a method wont to send data over the DNS protocol, a protocol which has never been intended for data transfer. due to that, people tend to overlook it and it's become a well-liked but effective tool in many attacks.Most popular use case for DNS tunneling is obtaining free internet through bypassing captive portals at airports, hotels, or if you are feeling patient the not-so-cheap on the wing Wi-Fi.On those shared internet hotspots HTTP traffic is blocked until a username/password is provided, however DNS traffic is usually still allowed within the background: we will encode our HTTP traffic over DNS and voila, we've internet access.This sounds fun but reality is, browsing anything on DNS tunneling is slow. Like, back to 1998 slow.Another more dangerous use of DNS tunneling would be bypassing network security devices (Firewalls, DLP appliances...) to line up an immediate and unmonitored communications channel on an organisation's network. Possibilities here are endless: Data exfiltration, fixing another penetration testing tool... you name it.To make it even more worrying, there's an outsized amount of easy to use DNS tunneling tools out there.There's even a minimum of one VPN over DNS protocol provider (warning: the planning of the web site is hideous, making me doubt on the legitimacy of it).As a pentester all this is often great, as a network admin not such a lot .
How does it work:For those that ignoramus about DNS protocol but still made it here, i feel you deserve a really brief explanation on what DNS does: DNS is sort of a phonebook for the web , it translates URLs (human-friendly language, the person's name), into an IP address (machine-friendly language, the phone number). That helps us remember many websites, same as we will remember many people's names.For those that know what DNS is i might suggest looking here for a fast refresh on DNS protocol, but briefly what you would like to understand is:* A Record: Maps a website name to an IP address.example.com ? 12.34.52.67* NS Record (a.k.a. Nameserver record): Maps a website name to an inventory of DNS servers, just in case our website is hosted in multiple servers.example.com ? server1.example.com, server2.example.comWho is involved in DNS tunneling?* Client. Will launch DNS requests with data in them to a website .* One Domain that we will configure. So DNS servers will redirect its requests to an outlined server of our own.* Server. this is often the defined nameserver which can ultimately receive the DNS requests.The 6 Steps in DNS tunneling (simplified):1. The client encodes data during a DNS request. The way it does this is often by prepending a bit of knowledge within the domain of the request. for instance : mypieceofdata.server1.example.com2. The DNS request goes bent a DNS server.3. The DNS server finds out the A register of your domain with the IP address of your server.4. The request for mypieceofdata.server1.example.com is forwarded to the server.5. The server processes regardless of the mypieceofdata was alleged to do. Let's assume it had been an HTTP request.6. The server replies back over DNS and woop woop, we've got signal.

Developed by Robert "RSnake" Hansen, Slowloris is DDoS attack software that permits one computer to require down an internet server. Due the straightforward yet elegant nature of this attack, it requires minimal bandwidth to implement and affects the target server's web server only, with almost no side effects on other services and ports. Slowloris has proven highly-effective against many popular sorts of web server software, including Apache 1.x and 2.x. Over the years, Slowloris has been credited with variety of high-profile server takedowns. Notably, it had been used extensively by Iranian 'hackivists' following the 2009 Iranian presidential election to attack Iranian government internet sites . Slowloris works by opening multiple connections to the targeted web server and keeping them open as long as possible. It does this by continuously sending partial HTTP requests, none of which are ever completed. The attacked servers open more and connections open, expecting each of the attack requests to be completed. Periodically, the Slowloris sends subsequent HTTP headers for every request, but never actually completes the request. Ultimately, the targeted server's maximum concurrent connection pool is filled, and extra (legitimate) connection attempts are denied. By sending partial, as against malformed, packets, Slowloris can easily elapse traditional Intrusion Detection systems. Named after a kind of slow-moving Asian primate, Slowloris really does win the race by moving slowly and steadily. A Slowloris attack must await sockets to be released by legitimate requests before consuming them one by one. For a high-volume internet site , this will take a while . the method are often further slowed if legitimate sessions are reinitiated. But within the end, if the attack is unmitigated, Slowloris-like the tortoise-wins the race. If undetected or unmitigated, Slowloris attacks also can last for long periods of your time . When attacked sockets outing , Slowloris simply reinitiates the connections, continuing to reach the online server until mitigated. Designed for stealth also as efficacy, Slowloris are often modified to send different host headers within the event that a virtual host is targeted, and logs are stored separately for every virtual host. More importantly, within the course of an attack, Slowloris are often set to suppress log file creation. this suggests the attack can catch unmonitored servers off-guard, with none red flags appearing in log file entries. Methods of mitigation Imperva's security services are enabled by reverse proxy technology, used for inspection of all incoming requests on their thanks to the clients' servers. Imperva's secured proxy won't forward any partial connection requests-rendering all Slowloris DDoS attack attempts completely and utterly useless.