{"id":9740,"date":"2016-03-01T15:03:33","date_gmt":"2016-03-01T13:03:33","guid":{"rendered":"http:\/\/blog.natro.com\/?p=9740"},"modified":"2019-09-30T10:26:35","modified_gmt":"2019-09-30T07:26:35","slug":"ddos-nedir-nasil-korunulabilir","status":"publish","type":"post","link":"https:\/\/www.natro.com\/blog\/ddos-nedir-nasil-korunulabilir\/","title":{"rendered":"DDoS Nedir? Nas\u0131l Korunulabilir?"},"content":{"rendered":"<p><span style=\"font-size: 16px;\">DOS(Denial Of Service) , sistemleri \u00e7al\u0131\u015famaz hale getirmek i\u00e7in yap\u0131lan bir sald\u0131r\u0131 tipidir. Bu sald\u0131r\u0131 sonu\u00e7lar\u0131na ise <strong>DDoS (Distrubuted Denial of Service)<\/strong> denmektedir. Sald\u0131r\u0131lar\u0131n organize bir bi\u00e7imde fazla kaynakla yap\u0131lmas\u0131d\u0131r. y\u00fczlerce hatta binlerce\u00a0 sald\u0131r\u0131 yap\u0131larak ger\u00e7ekle\u015ftirilir. \u0130nternet d\u00fcnyas\u0131 i\u00e7in hi\u00e7 eksilmeyen global bir tehdittir DDOS.<\/span><\/p>\n<p><!--more--><\/p>\n<p><span style=\"font-size: 16px;\">Ama\u00e7 sistemlere s\u0131zma de\u011fil, bilgisayar sistemlerine ula\u015farak\u00a0 ilgili t\u00fcm i\u015flevleri devre d\u0131\u015f\u0131 b\u0131rakmakt\u0131r. E postalar, web siteleri, telefon sistemleri hatta internet bankac\u0131l\u0131\u011f\u0131 <strong>DDOS <\/strong>\u2018a maruz kalarak durdurulan hizmetlerdendir. Sald\u0131r\u0131da genel olarak\u00a0 ya sahte <strong>IP <\/strong>ya da <strong>Zombi\/Botnet<\/strong>\u2018ler kullan\u0131lmaktad\u0131r. Genel olarak siber sald\u0131rganlarda ortak olarak g\u00f6r\u00fclen \u00f6zelli\u011fi DDOS\u2019 da da g\u00f6r\u00fcr\u00fcz. Sald\u0131rgan kendini gizler ve engellemesi\u00a0 zordur \u00e7\u00fcnk\u00fc sald\u0131rgan\u0131n hedef sunucuya direk ba\u011flanmas\u0131 gerekmedi\u011finden bulunmas\u0131 da neredeyse imkans\u0131zd\u0131r. Sistemde bir g\u00fcvenlik a\u00e7\u0131\u011f\u0131 bulunamamas\u0131, politik ve ticari sebepler, kendini kan\u0131tlama \u00e7abas\u0131 hatta keyfi istekler dahi DDOS \u2018u ger\u00e7ekle\u015ftirenler i\u00e7in sebep olarak s\u0131ralanabilir. O halde \u015funu rahatl\u0131kla s\u00f6yleyebiliriz ki hedeflenen sistemdeki her hangi bir zafiyet <strong>DDOS sald\u0131r\u0131s\u0131na<\/strong> b\u00fcy\u00fck \u00f6l\u00e7\u00fcde zemin olu\u015fturmaktad\u0131r.<\/span><\/p>\n<p><img decoding=\"async\" class=\"alignnone size-full wp-image-9748\" src=\"https:\/\/www.natro.com\/blog\/wp-content\/uploads\/2016\/02\/ddos-nedir.jpg\" alt=\"ddos-nedir\" width=\"800\" height=\"302\" \/><\/p>\n<p><span style=\"font-size: 16px;\">Yak\u0131n tarihteki pop\u00fcler DDOS sald\u0131r\u0131lar\u0131na 2010 Wikileaks destek\u00e7ileri taraf\u0131ndan b\u00fcy\u00fck kredi kart\u0131 \u015firketleri aleyhine 2010 y\u0131l\u0131nda d\u00fczenlenen sald\u0131r\u0131,\u00a0Mavi Marmara, Youtube protestosunu, 2008- G\u00fcrcistan, Estonya siber sald\u0131r\u0131lar\u0131n\u0131, 2007 Root DNS sald\u0131r\u0131lar\u0131n\u0131 \u00f6rnek verebiliriz. \u00d6zellikle 2010 y\u0131l\u0131ndaki Mavi Marmara protestosunda T\u00fcrkiye\u2019den misilleme olarak g\u00f6n\u00fcll\u00fc bir <strong>DDOS sald\u0131r\u0131s\u0131<\/strong> gelmi\u015fti. Sald\u0131r\u0131 ile \u0130srail h\u00fck\u00fcmetini websitesine eri\u015fimin durmas\u0131yla birlikte \u0130srail, k\u0131sa s\u00fcrede T\u00fcrkiye\u2019den gelen istekleri engelleyerek bu \u015fekilde bir \u00e7\u00f6z\u00fcm bulmu\u015ftu. \u00a0Bu nedenle DDOS sald\u0131r\u0131lar\u0131n\u0131n \u00f6zellikle kurumlar i\u00e7in tehlike olu\u015fturdu\u011funu s\u00f6ylememiz gerekir. \u00d6rne\u011fin a\u015fa\u011f\u0131daki g\u00f6rselde devlet sistemlerine y\u00f6nelik toplu bir DDOS sonras\u0131nda al\u0131nm\u0131\u015f web site\u00a0 g\u00f6r\u00fcnt\u00fcleri\u00a0yer almaktad\u0131r.<\/span><\/p>\n<p>\u00a0<\/p>\n<p><span style=\"font-size: 16px;\">D\u00fc\u015f\u00fcn\u00fcld\u00fc\u011f\u00fcnde, \u015firketler i\u00e7in en ba\u015fta itibar zedelenmesi, g\u00fcven kayb\u0131, h\u0131rs\u0131zl\u0131k neticesinde \u00a0ya\u015fanan maddi kay\u0131plar gibi bir \u00e7ok etkileri s\u0131ralanabilir DDOS sald\u0131r\u0131lar\u0131n\u0131n. Peki <strong>nas\u0131l korunabiliriz<\/strong> sorusuna nas\u0131l yan\u0131t arar\u0131z? Tamamen korunabilece\u011fi yanl\u0131\u015f bilinen bilgiler aras\u0131ndad\u0131r. Maalesef hi\u00e7 bir \u00f6nlem tam olarak \u00a0yeterli de\u011fildir. Tek ba\u015f\u0131na Firewall, DDOS engelleme ara\u00e7lar\u0131, anti-vir\u00fcs programlar\u0131 ya da Linux\u2019un DDOS i\u00e7in daha dayan\u0131kl\u0131 oldu\u011fu da yanl\u0131\u015f bilinen bilgiler aras\u0131ndad\u0131r.<\/span><\/p>\n<p><span style=\"font-size: 16px;\">Sihirli y\u00f6ntemler s\u0131ralamam\u0131z g\u00fc\u00e7t\u00fcr ancak hem \u015firket servis sa\u011flay\u0131c\u0131lar\u0131 hem de ev kullan\u0131c\u0131lar\u0131 i\u00e7in bir ka\u00e7 \u00f6neride bulunabiliriz. \u00d6zellikle kurumlarda sald\u0131r\u0131dan korunmada en b\u00fcy\u00fck \u00f6nlemleri; <strong>Network <\/strong>yap\u0131s\u0131n\u0131 iyi tasarlamak, sistemi iyi bilen \u00e7al\u0131\u015fanlarla sahip olmak ve bu \u00e7al\u0131\u015fanlar\u0131n\u00a0 TCP\/IP bilgisinin yeterli d\u00fczeyde olmas\u0131n\u0131 sa\u011flamak olarak s\u0131ralayabiliriz.<strong> G\u00fcvenlik duvar\u0131 seviyesinde koruma <\/strong>i\u00e7in ise \u015funlar\u0131 s\u00f6yleyebilmem m\u00fcmk\u00fcnd\u00fcr. E\u011fer cihaz\u0131m\u0131z destekliyorsa,\u00a0 rate limiting yani belirli bir adres \u00fczerinden gelen maksimum paket say\u0131s\u0131n\u0131 belirleyip e\u015fik de\u011ferini a\u015fan ip adreslerinin bloklanmas\u0131 \u00f6zelli\u011finin aktif edilmesi korumada b\u00fcy\u00fck oranda etkili olmaktad\u0131r. <strong>Sald\u0131r\u0131 tespiti ve engellenmesi olarak koruma<\/strong> da olduk\u00e7a \u00f6nem arz etmektedir. IPS\u2019ler t\u00fcm <strong>DOS\/DDOS<\/strong> sald\u0131r\u0131lar\u0131n\u0131 veri tabanlar\u0131nda bar\u0131nd\u0131rmaktad\u0131rlar. Bu y\u00fczden IPS\u2019ler \u00fczerinde ilk yap\u0131lacak i\u015flem, imzalar\u0131n devreye al\u0131nmas\u0131d\u0131r. Ayn\u0131 \u015fekilde destekliyorsa IPS \u00fczerinde syncooki\u2019nin devreye al\u0131nmas\u0131 da sald\u0131r\u0131lar\u0131n etkilerini azaltacakt\u0131r. Basit <strong>ev kullan\u0131c\u0131lar\u0131 i\u00e7in<\/strong> ise bir ka\u00e7 koruma \u00f6nerisi s\u0131ralayabiliriz \u015fu \u015fekilde. Ev kullan\u0131c\u0131lar\u0131 genel olarak vir\u00fcs ve malware yaz\u0131l\u0131mlar\u0131n\u0131n hedefi konumundad\u0131rlar. Bu y\u00fczden bilgisayarlara mutlak suretle bir anti-vir\u00fcs yaz\u0131l\u0131m\u0131 y\u00fcklenmelidir. Piyasa \u00fczerinde ara\u015ft\u0131r\u0131ld\u0131\u011f\u0131nda bu anlamda destek veren kaliteli programlara kolayl\u0131kla ula\u015f\u0131labilir. Yaz\u0131l\u0131mlar\u0131n g\u00fcncelli\u011fi ise ev kullan\u0131c\u0131lar\u0131 i\u00e7in kontrol edilmesi gereken bir di\u011fer \u00f6nemli etkendir.<\/span><\/p>\n<p><span style=\"font-size: 16px;\">Web sunucular \u015firketlerin kurumsal kimlik y\u00fcz\u00fc oldu\u011fu i\u00e7in sald\u0131r\u0131y\u0131 ilk alan sistemlerdir. \u00a0Belirgin g\u00f6r\u00fclen GET flood sald\u0131r\u0131lar\u0131nda, sald\u0131rgan sunucu kapasitesini zorlayarak\u00a0 site eri\u015fimini engelleme giri\u015fiminde bulunur. Bu ba\u011flamda <strong>web sunuculara y\u00f6nelik koruma<\/strong>da \u00a0g\u00fcvenlik duvar\u0131na koyulan rate limiting \u00f6zelli\u011fi, web sunuculara koyulan g\u00fc\u00e7l\u00fc y\u00fck dengeleyici cihazlar ve ters proxy sistemleri olduk\u00e7a etkilidir.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"DOS(Denial Of Service) , sistemleri \u00e7al\u0131\u015famaz hale getirmek i\u00e7in yap\u0131lan bir sald\u0131r\u0131 tipidir. Bu sald\u0131r\u0131 sonu\u00e7lar\u0131na ise DDoS&hellip;\n","protected":false},"author":7,"featured_media":11197,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[39],"tags":[],"class_list":{"0":"post-9740","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-hosting"},"_links":{"self":[{"href":"https:\/\/www.natro.com\/blog\/wp-json\/wp\/v2\/posts\/9740","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.natro.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.natro.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.natro.com\/blog\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/www.natro.com\/blog\/wp-json\/wp\/v2\/comments?post=9740"}],"version-history":[{"count":0,"href":"https:\/\/www.natro.com\/blog\/wp-json\/wp\/v2\/posts\/9740\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.natro.com\/blog\/wp-json\/wp\/v2\/media\/11197"}],"wp:attachment":[{"href":"https:\/\/www.natro.com\/blog\/wp-json\/wp\/v2\/media?parent=9740"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.natro.com\/blog\/wp-json\/wp\/v2\/categories?post=9740"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.natro.com\/blog\/wp-json\/wp\/v2\/tags?post=9740"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}