{"id":476877,"date":"2023-08-09T09:04:34","date_gmt":"2023-08-09T09:04:34","guid":{"rendered":""},"modified":"2023-09-05T11:13:37","modified_gmt":"2023-09-05T11:13:37","slug":"dns-amplification-attack","status":"publish","type":"wiki","link":"https:\/\/oneproxy.pro\/pt\/wiki\/dns-amplification-attack\/","title":{"rendered":"Ataque de amplifica\u00e7\u00e3o de DNS"},"content":{"rendered":"<h2>Introdu\u00e7\u00e3o<\/h2>\n<p>DNS (Domain Name System) \u00e9 um componente cr\u00edtico da infraestrutura da Internet que traduz nomes de dom\u00ednio em endere\u00e7os IP, permitindo que os usu\u00e1rios acessem sites por seus nomes familiares. Embora o DNS sirva como base da Internet, ele tamb\u00e9m \u00e9 suscet\u00edvel a v\u00e1rias amea\u00e7as \u00e0 seguran\u00e7a, uma das quais \u00e9 o ataque de amplifica\u00e7\u00e3o do DNS. Este artigo investiga a hist\u00f3ria, a mec\u00e2nica, os tipos e as contramedidas do ataque de amplifica\u00e7\u00e3o de DNS.<\/p>\n<h2>A Origem e Primeira Men\u00e7\u00e3o<\/h2>\n<p>O ataque de amplifica\u00e7\u00e3o de DNS, tamb\u00e9m conhecido como ataque de reflex\u00e3o de DNS, surgiu pela primeira vez no in\u00edcio dos anos 2000. A t\u00e9cnica de explorar servidores DNS para amplificar o impacto dos ataques DDoS (Distributed Denial of Service) foi atribu\u00edda a um invasor chamado \u201cDale Drew\u201d. Em 2002, Dale Drew demonstrou esse tipo de ataque, aproveitando a infraestrutura do DNS para inundar um alvo com tr\u00e1fego excessivo, causando interrup\u00e7\u00e3o do servi\u00e7o.<\/p>\n<h2>Informa\u00e7\u00f5es detalhadas sobre ataque de amplifica\u00e7\u00e3o de DNS<\/h2>\n<p>O ataque de amplifica\u00e7\u00e3o de DNS explora o comportamento inerente de determinados servidores DNS para responder a grandes consultas de DNS com respostas ainda maiores. Ele aproveita resolvedores de DNS abertos, que aceitam e respondem a consultas de DNS de qualquer fonte, em vez de responder apenas a consultas de dentro de sua pr\u00f3pria rede.<\/p>\n<h2>Estrutura interna do ataque de amplifica\u00e7\u00e3o de DNS<\/h2>\n<p>O ataque de amplifica\u00e7\u00e3o de DNS normalmente envolve as seguintes etapas:<\/p>\n<ol>\n<li>\n<p><strong>IP de origem falsificado:<\/strong> O invasor falsifica seu endere\u00e7o IP de origem, fazendo com que ele apare\u00e7a como o endere\u00e7o IP da v\u00edtima.<\/p>\n<\/li>\n<li>\n<p><strong>Consulta DNS:<\/strong> O invasor envia uma consulta DNS para um nome de dom\u00ednio espec\u00edfico para um resolvedor DNS aberto, fazendo parecer que a solicita\u00e7\u00e3o vem da v\u00edtima.<\/p>\n<\/li>\n<li>\n<p><strong>Resposta Amplificada:<\/strong> O resolvedor de DNS aberto, assumindo que a solicita\u00e7\u00e3o \u00e9 leg\u00edtima, responde com uma resposta de DNS muito maior. Esta resposta \u00e9 enviada para o endere\u00e7o IP da v\u00edtima, sobrecarregando a capacidade da rede.<\/p>\n<\/li>\n<li>\n<p><strong>Efeito DDoS:<\/strong> Com v\u00e1rios resolvedores de DNS abertos enviando respostas amplificadas ao IP da v\u00edtima, a rede do alvo fica inundada com tr\u00e1fego, levando \u00e0 interrup\u00e7\u00e3o do servi\u00e7o ou at\u00e9 mesmo \u00e0 nega\u00e7\u00e3o completa do servi\u00e7o.<\/p>\n<\/li>\n<\/ol>\n<h2>Principais recursos do ataque de amplifica\u00e7\u00e3o de DNS<\/h2>\n<ul>\n<li>\n<p><strong>Fator de Amplifica\u00e7\u00e3o:<\/strong> O fator de amplifica\u00e7\u00e3o \u00e9 uma caracter\u00edstica crucial deste ataque. Representa a propor\u00e7\u00e3o entre o tamanho da resposta DNS e o tamanho da consulta DNS. Quanto maior o fator de amplifica\u00e7\u00e3o, mais prejudicial ser\u00e1 o ataque.<\/p>\n<\/li>\n<li>\n<p><strong>Falsifica\u00e7\u00e3o de origem de tr\u00e1fego:<\/strong> Os invasores falsificam o endere\u00e7o IP de origem em suas consultas DNS, tornando dif\u00edcil rastrear a verdadeira origem do ataque.<\/p>\n<\/li>\n<li>\n<p><strong>Reflex\u00e3o:<\/strong> O ataque usa resolvedores de DNS como amplificadores, refletindo e amplificando o tr\u00e1fego em dire\u00e7\u00e3o \u00e0 v\u00edtima.<\/p>\n<\/li>\n<\/ul>\n<h2>Tipos de ataque de amplifica\u00e7\u00e3o de DNS<\/h2>\n<p>Os ataques de amplifica\u00e7\u00e3o de DNS podem ser categorizados com base no tipo de registro DNS usado para o ataque. Os tipos comuns s\u00e3o:<\/p>\n<table>\n<thead>\n<tr>\n<th>Tipo de ataque<\/th>\n<th>Registro DNS usado<\/th>\n<th>Fator de Amplifica\u00e7\u00e3o<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>DNS normal<\/td>\n<td>A<\/td>\n<td>1-10x<\/td>\n<\/tr>\n<tr>\n<td>DNSSEC<\/td>\n<td>QUALQUER<\/td>\n<td>20-30x<\/td>\n<\/tr>\n<tr>\n<td>DNSSEC com EDNS0<\/td>\n<td>QUALQUER + EDNS0<\/td>\n<td>100-200x<\/td>\n<\/tr>\n<tr>\n<td>Dom\u00ednio Inexistente<\/td>\n<td>QUALQUER<\/td>\n<td>100-200x<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Maneiras de usar ataques, problemas e solu\u00e7\u00f5es de amplifica\u00e7\u00e3o de DNS<\/h2>\n<h3>Maneiras de usar ataque de amplifica\u00e7\u00e3o de DNS<\/h3>\n<ol>\n<li>\n<p><strong>Ataques DDoS:<\/strong> O principal uso dos ataques de amplifica\u00e7\u00e3o de DNS \u00e9 lan\u00e7ar ataques DDoS contra alvos espec\u00edficos. Ao sobrecarregar a infra-estrutura do alvo, estes ataques visam interromper servi\u00e7os e causar tempo de inatividade.<\/p>\n<\/li>\n<li>\n<p><strong>Falsifica\u00e7\u00e3o de endere\u00e7o IP:<\/strong> O ataque pode ser usado para ofuscar a verdadeira origem de um ataque, aproveitando a falsifica\u00e7\u00e3o de endere\u00e7o IP, dificultando que os defensores rastreiem a origem com precis\u00e3o.<\/p>\n<\/li>\n<\/ol>\n<h3>Problemas e solu\u00e7\u00f5es<\/h3>\n<ul>\n<li>\n<p><strong>Resolvedores DNS abertos:<\/strong> O principal problema \u00e9 a exist\u00eancia de resolvedores DNS abertos na internet. Os administradores de rede devem proteger seus servidores DNS e configur\u00e1-los para responder apenas a consultas leg\u00edtimas de dentro de sua rede.<\/p>\n<\/li>\n<li>\n<p><strong>Filtragem de pacotes:<\/strong> ISPs e administradores de rede podem implementar filtragem de pacotes para impedir que consultas DNS com IPs de origem falsificados saiam de suas redes.<\/p>\n<\/li>\n<li>\n<p><strong>Limita\u00e7\u00e3o da taxa de resposta DNS (DNS RRL):<\/strong> A implementa\u00e7\u00e3o de DNS RRL em servidores DNS pode ajudar a mitigar o impacto dos ataques de amplifica\u00e7\u00e3o de DNS, limitando a taxa com que eles respondem a consultas de endere\u00e7os IP espec\u00edficos.<\/p>\n<\/li>\n<\/ul>\n<h2>Principais caracter\u00edsticas e compara\u00e7\u00f5es<\/h2>\n<table>\n<thead>\n<tr>\n<th>Caracter\u00edstica<\/th>\n<th>Ataque de amplifica\u00e7\u00e3o de DNS<\/th>\n<th>Ataque de falsifica\u00e7\u00e3o de DNS<\/th>\n<th>Envenenamento de cache DNS<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Objetivo<\/td>\n<td>DDoS<\/td>\n<td>Manipula\u00e7\u00e3o de dados<\/td>\n<td>Manipula\u00e7\u00e3o de dados<\/td>\n<\/tr>\n<tr>\n<td>Tipo de ataque<\/td>\n<td>Baseado em reflex\u00e3o<\/td>\n<td>Homem no meio<\/td>\n<td>Baseado em inje\u00e7\u00e3o<\/td>\n<\/tr>\n<tr>\n<td>Fator de Amplifica\u00e7\u00e3o<\/td>\n<td>Alto<\/td>\n<td>Baixo<\/td>\n<td>Nenhum<\/td>\n<\/tr>\n<tr>\n<td>N\u00edvel de risco<\/td>\n<td>Alto<\/td>\n<td>M\u00e9dio<\/td>\n<td>M\u00e9dio<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Perspectivas e Tecnologias Futuras<\/h2>\n<p>A batalha contra os ataques de amplifica\u00e7\u00e3o de DNS continua a evoluir, com investigadores e especialistas em seguran\u00e7a cibern\u00e9tica a desenvolver constantemente novas t\u00e9cnicas de mitiga\u00e7\u00e3o. As tecnologias futuras podem incluir:<\/p>\n<ul>\n<li>\n<p><strong>Defesas baseadas em aprendizado de m\u00e1quina:<\/strong> Empregar algoritmos de aprendizado de m\u00e1quina para detectar e mitigar ataques de amplifica\u00e7\u00e3o de DNS em tempo real.<\/p>\n<\/li>\n<li>\n<p><strong>Implementa\u00e7\u00e3o DNSSEC:<\/strong> A ado\u00e7\u00e3o ampla de DNSSEC (Extens\u00f5es de Seguran\u00e7a do Sistema de Nomes de Dom\u00ednio) pode ajudar na preven\u00e7\u00e3o de ataques de amplifica\u00e7\u00e3o de DNS que exploram o registro ANY.<\/p>\n<\/li>\n<\/ul>\n<h2>Servidores proxy e ataque de amplifica\u00e7\u00e3o de DNS<\/h2>\n<p>Os servidores proxy, incluindo aqueles fornecidos pelo OneProxy, podem inadvertidamente tornar-se parte de ataques de amplifica\u00e7\u00e3o de DNS se forem configurados incorretamente ou permitirem tr\u00e1fego DNS de qualquer origem. Os provedores de servidores proxy devem tomar medidas para proteger seus servidores e impedi-los de participar de tais ataques.<\/p>\n<h2>Links Relacionados<\/h2>\n<p>Para obter mais informa\u00e7\u00f5es sobre ataques de amplifica\u00e7\u00e3o de DNS, considere explorar os seguintes recursos:<\/p>\n<ol>\n<li><a href=\"https:\/\/us-cert.cisa.gov\/ncas\/alerts\/TA13-088A\" target=\"_new\" rel=\"noopener nofollow\">Alerta US-CERT (TA13-088A): ataques de amplifica\u00e7\u00e3o de DNS<\/a><\/li>\n<li><a href=\"https:\/\/tools.ietf.org\/html\/rfc5358\" target=\"_new\" rel=\"noopener nofollow\">RFC 5358 \u2013 Prevenindo o uso de servidores DNS recursivos em ataques refletores<\/a><\/li>\n<li><a href=\"https:\/\/www.akamai.com\/us\/en\/multimedia\/documents\/white-paper\/dns-amplification-attacks-and-response-policy-zones-wp.pdf\" target=\"_new\" rel=\"noopener nofollow\">Ataques de amplifica\u00e7\u00e3o de DNS e zonas de pol\u00edtica de resposta (RPZ)<\/a><\/li>\n<\/ol>\n<p>Lembre-se de que conhecimento e conscientiza\u00e7\u00e3o s\u00e3o essenciais para combater amea\u00e7as cibern\u00e9ticas, como ataques de amplifica\u00e7\u00e3o de DNS. Mantenha-se informado, vigilante e proteja sua infraestrutura de Internet para se proteger contra esses perigos potenciais.<\/p>","protected":false},"featured_media":476878,"menu_order":0,"template":"","meta":{"_acf_changed":false,"content-type":"","inline_featured_image":false,"footnotes":""},"class_list":["post-476877","wiki","type-wiki","status-publish","has-post-thumbnail","hentry"],"acf":{"faq_title":"Frequently Asked Questions about <mark>DNS Amplification Attack: Unveiling the Threat<\/mark>","faq_items":[{"question":"What is a DNS amplification attack?","answer":"<p>A DNS amplification attack is a type of cyber threat that exploits open DNS resolvers to flood a target's network with overwhelming traffic. The attacker sends DNS queries with forged source IP addresses to these open resolvers, which then respond with much larger DNS responses, amplifying the traffic directed towards the victim. This can lead to a Distributed Denial of Service (DDoS) situation, disrupting the target's services.<\/p>"},{"question":"How did DNS amplification attacks originate?","answer":"<p>The first mention of DNS amplification attacks can be traced back to the early 2000s, with an attacker named \"Dale Drew\" demonstrating this technique. By leveraging open DNS resolvers, he showcased how attackers could magnify the impact of DDoS attacks, causing service disruptions.<\/p>"},{"question":"How does a DNS amplification attack work?","answer":"<p>The internal structure of a DNS amplification attack involves several steps. First, the attacker spoofs their source IP address to make it appear as the victim's IP. Then, they send DNS queries to open DNS resolvers, making it seem like the requests are coming from the victim. The open resolvers, assuming the requests are legitimate, respond with larger DNS responses, which flood the victim's network, causing a DDoS effect.<\/p>"},{"question":"What are the key features of DNS amplification attacks?","answer":"<p>The key features of DNS amplification attacks include the amplification factor, which represents the ratio of DNS response size to query size. Additionally, traffic source spoofing is used to hide the true origin of the attack. Reflection is also a crucial aspect, as open DNS resolvers amplify the attack traffic towards the victim.<\/p>"},{"question":"What types of DNS amplification attacks exist?","answer":"<p>DNS amplification attacks can be categorized based on the type of DNS record used for the attack. Common types include Regular DNS, DNSSEC, DNSSEC with EDNS0, and Non-Existent Domain attacks. Each type varies in its amplification factor and potential impact on the target.<\/p>"},{"question":"How can DNS amplification attacks be used, and what are the problems and solutions?","answer":"<p>DNS amplification attacks are primarily used to launch DDoS attacks, causing service disruptions. The main problem lies in the existence of open DNS resolvers, which attackers exploit. Solutions include securing DNS servers, implementing packet filtering, and using DNS Response Rate Limiting (DNS RRL).<\/p>"},{"question":"How does DNS amplification attack compare with other DNS-related threats?","answer":"<p>DNS amplification attacks differ from DNS spoofing attacks and DNS cache poisoning. While DNS amplification aims for DDoS, DNS spoofing manipulates data and DNS cache poisoning injects false data into DNS caches.<\/p>"},{"question":"What are the future perspectives and technologies related to DNS amplification attacks?","answer":"<p>The future holds promising technologies, such as machine learning-based defenses and wider adoption of DNSSEC, to mitigate DNS amplification attacks effectively.<\/p>"},{"question":"How are proxy servers associated with DNS amplification attacks?","answer":"<p>Proxy servers, like those provided by OneProxy, may inadvertently be part of DNS amplification attacks if misconfigured or allowing DNS traffic from any source. OneProxy ensures secure servers, preventing such risks.<\/p>"},{"question":"Where can I find more information about DNS amplification attacks?","answer":"<p>For further information, you can explore the following resources:<\/p><ol><li><a href=\"https:\/\/us-cert.cisa.gov\/ncas\/alerts\/TA13-088A\" target=\"_new\">US-CERT Alert (TA13-088A): DNS Amplification Attacks<\/a><\/li><li><a href=\"https:\/\/tools.ietf.org\/html\/rfc5358\" target=\"_new\">RFC 5358 - Preventing Use of Recursive DNS Servers in Reflector Attacks<\/a><\/li><li><a href=\"https:\/\/www.akamai.com\/us\/en\/multimedia\/documents\/white-paper\/dns-amplification-attacks-and-response-policy-zones-wp.pdf\" target=\"_new\">DNS Amplification Attacks and Response Policy Zones (RPZ)<\/a><\/li><\/ol>"}]},"_links":{"self":[{"href":"https:\/\/oneproxy.pro\/pt\/wp-json\/wp\/v2\/wiki\/476877","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/oneproxy.pro\/pt\/wp-json\/wp\/v2\/wiki"}],"about":[{"href":"https:\/\/oneproxy.pro\/pt\/wp-json\/wp\/v2\/types\/wiki"}],"version-history":[{"count":0,"href":"https:\/\/oneproxy.pro\/pt\/wp-json\/wp\/v2\/wiki\/476877\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/oneproxy.pro\/pt\/wp-json\/wp\/v2\/media\/476878"}],"wp:attachment":[{"href":"https:\/\/oneproxy.pro\/pt\/wp-json\/wp\/v2\/media?parent=476877"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}