{"id":2143,"date":"2014-07-18T08:00:38","date_gmt":"2014-07-18T06:00:38","guid":{"rendered":"http:\/\/preventista.sk\/info\/?p=2143"},"modified":"2014-07-18T00:46:36","modified_gmt":"2014-07-17T22:46:36","slug":"spustite-siet-2-ked-sa-vam-sluzba-odoprie","status":"publish","type":"post","link":"https:\/\/preventista.sk\/info\/spustite-siet-2-ked-sa-vam-sluzba-odoprie\/","title":{"rendered":"&#8222;Spustite sie\u0165! 2&#8220; &#8211; Ke\u010f sa v\u00e1m slu\u017eba odoprie"},"content":{"rendered":"<h1><\/h1>\n<p>&nbsp;<\/p>\n<h1>&#8222;Spustite sie\u0165! 2&#8220; &#8211;\u00a0Ke\u010f sa v\u00e1m slu\u017eba odoprie<\/h1>\n<p>Prv\u00e1 \u010das\u0165 n\u00e1m stru\u010dne pribl\u00ed\u017eila problematiku sie\u0165ovej bezpe\u010dnosti a\u00a0s\u00a0\u0148ou s\u00favisiace \u00fatoky na 3 z\u00e1kladn\u00e9 piliere bezpe\u010dnosti \u2013 <strong>d\u00f4vernos\u0165, integrita, dostupnos\u0165.<\/strong><\/p>\n<p>Nasleduj\u00faci \u010dl\u00e1nok n\u00e1m podrobne pribl\u00ed\u017ei \u00fatok vo\u010di dostupnosti\u00a0 (DoS, resp. DDoS) a\u00a0tie\u017e sp\u00f4soby ako sa pred t\u00fdmito \u00fatokmi chr\u00e1ni\u0165.<\/p>\n<p>&nbsp;<\/p>\n<h2>DoS<\/h2>\n<hr \/>\n<p>Pri \u00fatoku <strong>DoS<\/strong> \u2013 <strong>Denial of Service<\/strong> \u2013 <strong>odopretie slu\u017eby<\/strong> sa \u00fato\u010dn\u00edk pok\u00fa\u0161a zabr\u00e1ni\u0165 opr\u00e1vnen\u00fdm u\u017e\u00edvate\u013eom v\u00a0pr\u00edstupe k\u00a0slu\u017ebe alebo k\u00a0inform\u00e1ci\u00e1m. \u00datokom na server a\u00a0jeho pripojenie \u00a0m\u00f4\u017ee \u00fato\u010dn\u00edk znemo\u017eni\u0165 pr\u00edstup u\u017e\u00edvate\u013eov k\u00a0elektronickej po\u0161te, webovej str\u00e1nke, online bankovn\u00edctvu a\u00a0pod., pr\u00edpadne k\u00a0in\u00fdm slu\u017eb\u00e1m ktor\u00e9 s\u00fa na danom servery spusten\u00e9. \u00datok nemus\u00ed by\u0165 nutne zameran\u00fd na server, v\u00a0men\u0161om mer\u00edtku to m\u00f4\u017ee by\u0165 aj v\u00e1\u0161 osobn\u00fd po\u010d\u00edta\u010d.<br \/>\n<a href=\"https:\/\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/DDoS-info.jpg\"><br \/>\n<\/a><\/p>\n<h2>DDoS<\/h2>\n<hr \/>\n<h2><\/h2>\n<p>Roz\u0161\u00edren\u00edm \u00fatoku <strong>DoS<\/strong> je<strong> DDoS<\/strong>, pri\u010dom sa jedn\u00e1 <strong>o\u00a0Distributed Denial of Service<\/strong>, teda distribuovan\u00e9 odopretie slu\u017eby. \u00dato\u010dn\u00edk m\u00f4\u017ee z\u00edska\u0165 kontrolu nad in\u00fdm po\u010d\u00edta\u010dom vyu\u017eit\u00edm bezpe\u010dnostn\u00fdch dier alebo slab\u00fdch miest v\u00a0syst\u00e9me, v\u00e4\u010d\u0161inou prostredn\u00edctvom \u0161kodliv\u00e9ho k\u00f3du typu \u201etr\u00f3jsky k\u00f4n\u201c. K\u00f3d je \u0161\u00edren\u00fd nen\u00e1padne a usadzuje sa v \u010do najv\u00e4\u010d\u0161om po\u010dte syst\u00e9mov pre ich neskor\u0161ie zneu\u017eitie. Z\u00a0takto ovl\u00e1dnut\u00e9ho po\u010d\u00edta\u010da sa st\u00e1va tzv. \u201e<strong>zombie<\/strong>\u201c.<\/p>\n<p>Pokia\u013e sa \u00fato\u010dn\u00edkovi podar\u00ed ovl\u00e1dnu\u0165 dostato\u010dn\u00e9 mno\u017estvo strojov, vznik\u00e1 sie\u0165 infikovan\u00fdch po\u010d\u00edta\u010dov ktor\u00e9 je mo\u017en\u00e9 dia\u013ekovo riadi\u0165 (tzv. \u201e<strong>botnet<\/strong>\u201c). Ak je u\u017e raz po\u010d\u00edta\u010d nakazen\u00fd, m\u00f4\u017ee by\u0165 ovl\u00e1dan\u00fd vzdialen\u00fdm pr\u00edstupom bez toho, aby o\u00a0tom majite\u013e stroja vedel. Po\u010d\u00edta\u010de v\u00a0sieti Botnet s\u00fa potom vyu\u017e\u00edvan\u00e9 ako s\u00fakromn\u00e1 arm\u00e1da, ktor\u00e1 m\u00f4\u017ee za\u00fato\u010di\u0165 na \u013eubovo\u013en\u00fd cie\u013e. Niektor\u00e9 Botnety sa m\u00f4\u017eu sklada\u0165 z\u00a0mili\u00f3nov po\u010d\u00edta\u010dov. Modern\u00e9 botnety s\u00fa zalo\u017een\u00e9 na \u0161kodlivom k\u00f3de, ktor\u00fd je univerz\u00e1lne konfigurovate\u013en\u00fd, relat\u00edvne \u013eahko distribuovate\u013en\u00fd a ktor\u00fd mnohokr\u00e1t obsahuje centr\u00e1lne riadiace prvky na \u00farovni profesion\u00e1lnych informa\u010dn\u00fdch syst\u00e9mov.<\/p>\n<p>Disponuj\u00fac efekt\u00edvnym <strong>botnetom<\/strong>, \u00fato\u010dn\u00edk m\u00f4\u017ee za\u010da\u0165 generova\u0165 prev\u00e1dzku vo\u010di zvolen\u00e9mu cie\u013eu. Botnet dok\u00e1\u017ee vygenerova\u0165 obrovsk\u00e9 mno\u017estv\u00e1 sie\u0165ovej komunik\u00e1cie a\u00a0tak pre\u0165a\u017ei\u0165 vybran\u00fd cie\u013e. T\u00e1to \u0161kodliv\u00e1 komunik\u00e1cia m\u00f4\u017ee by\u0165 generovan\u00e1 r\u00f4znymi sp\u00f4sobmi, napr. \u017eiadan\u00edm v\u00e4\u010d\u0161ieho mno\u017estva po\u017eiadaviek ako dok\u00e1\u017ee server znies\u0165, alebo zasielan\u00edm tak\u00e9to objemu n\u00e1hodn\u00fdch d\u00e1t, ktor\u00fd kompletne zahlt\u00ed pridelen\u00fa \u0161\u00edrku p\u00e1sma.<\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/Botnet.png?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"2177\" data-permalink=\"https:\/\/preventista.sk\/info\/spustite-siet-2-ked-sa-vam-sluzba-odoprie\/botnet\/\" data-orig-file=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/Botnet.png?fit=698%2C266&amp;ssl=1\" data-orig-size=\"698,266\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"Botnet\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/Botnet.png?fit=698%2C266&amp;ssl=1\" class=\"size-full wp-image-2177 aligncenter\" src=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/Botnet.png?resize=698%2C266&#038;ssl=1\" alt=\"Schema_botnet\" width=\"698\" height=\"266\" srcset=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/Botnet.png?w=698&amp;ssl=1 698w, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/Botnet.png?resize=320%2C121&amp;ssl=1 320w, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/Botnet.png?resize=450%2C171&amp;ssl=1 450w\" sizes=\"auto, (max-width: 698px) 100vw, 698px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>Vektor DDoS \u00fatoku je toto\u017en\u00fd s DoS; rozdiel spo\u010d\u00edva v decentraliz\u00e1cii zdroja \u00fatoku. Botnety pozost\u00e1vaj\u00fa\u00a0 r\u00e1dovo mnohokr\u00e1t zo st\u00e1tis\u00edcov zombie PC, preto \u00fato\u010dn\u00edk m\u00f4\u017ee v\u00a0rovnakom \u010dase z\u00a0r\u00f4znych miest odosiela\u0165 ve\u013ek\u00e9 mno\u017estv\u00e1 po\u017eiadaviek na server, ktor\u00fd ich jednoducho nebude schopn\u00fd spracov\u00e1va\u0165.<\/p>\n<p><strong>Botnety s\u00fa predmetom obchodovania na internetovom \u010diernom trhu. <\/strong>Existuje mnoho \u0161pecializovan\u00fdch \u010diernych online trhov, na ktor\u00fdch m\u00f4\u017eete preda\u0165 alebo k\u00fapi\u0165 jednotliv\u00e9 DDoS \u00fatoky. Vyu\u017e\u00edvan\u00edm t\u00fdchto undergroundov\u00fdch trhov m\u00f4\u017ee ktoko\u013evek zaplati\u0165 za zne\u0161kodnenie webstr\u00e1nky, \u010di u\u017e preto \u017ee nes\u00fahlas\u00ed s\u00a0obsahom ktor\u00fd uverej\u0148uje, alebo chce u\u0161kodi\u0165 organiz\u00e1cii ktor\u00e1 str\u00e1nku vlastn\u00ed. Jednoduch\u00fd t\u00fd\u017ede\u0148 trvaj\u00faci DDoS \u00fatok, ktor\u00fd dok\u00e1\u017ee polo\u017ei\u0165 str\u00e1nku men\u0161ej firmy v\u00e1s nebude st\u00e1\u0165 viac ako 150$.<\/p>\n<p><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"2151\" data-permalink=\"https:\/\/preventista.sk\/info\/spustite-siet-2-ked-sa-vam-sluzba-odoprie\/ddos-info\/\" data-orig-file=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/DDoS-info.jpg?fit=911%2C700&amp;ssl=1\" data-orig-size=\"911,700\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"DDoS info\" data-image-description=\"&lt;p&gt;DDoS pod mikroskopom infografika&lt;\/p&gt;\n\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/DDoS-info.jpg?fit=700%2C537&amp;ssl=1\" class=\"aligncenter size-full wp-image-2151\" src=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/DDoS-info.jpg?resize=911%2C700&#038;ssl=1\" alt=\"DDoS infografika\" width=\"911\" height=\"700\" srcset=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/DDoS-info.jpg?w=911&amp;ssl=1 911w, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/DDoS-info.jpg?resize=320%2C245&amp;ssl=1 320w, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/DDoS-info.jpg?resize=450%2C345&amp;ssl=1 450w, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/DDoS-info.jpg?resize=700%2C537&amp;ssl=1 700w\" sizes=\"auto, (max-width: 911px) 100vw, 911px\" \/><\/p>\n<p>&nbsp;<\/p>\n<hr \/>\n<p>Spolo\u010dnosti Google Ideas a\u00a0Arbor networks vytvorili spolo\u010dn\u00fd projekt, kde si m\u00f4\u017eete pozrie\u0165 pr\u00e1ve prebiehaj\u00face DDoS \u00fatoky. Zobraz\u00ed v\u00e1m \u0161\u00edrku p\u00e1sma ktor\u00fa vyu\u017e\u00edvaj\u00fa, o\u00a0ak\u00fd typ \u00fatoku sa jedn\u00e1, \u00fatoky v\u00a0jednotliv\u00fdch krajin\u00e1ch a\u00a0podobne. Digit\u00e1lnu mapu n\u00e1jdete na str\u00e1nke\u00a0<a href=\"http:\/\/www.digitalattackmap.com\/\">http:\/\/www.digitalattackmap.com\/<\/a><\/p>\n<p><iframe loading=\"lazy\" src=\"\/\/www.youtube.com\/embed\/v7sK9hMYU90?rel=0\" width=\"420\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>&nbsp;<\/p>\n<h1>Typy \u00fatokov na odopretie slu\u017eby<\/h1>\n<hr \/>\n<h1><\/h1>\n<p>DoS \u00fatoky sa delia do nieko\u013ek\u00fdch kateg\u00f3ri\u00ed pod\u013ea toho, na ak\u00fa \u010das\u0165 syst\u00e9mu \u00fato\u010dia. \u00dato\u010dn\u00edk sa m\u00f4\u017ee zamera\u0165 na:<\/p>\n<ul>\n<li>spotreba zdrojov stroja, napr. \u201ezaplaven\u00edm\u201c prev\u00e1dzky n\u00e1hodn\u00fdmi d\u00e1tami, ktor\u00e9 zabra\u0148uj\u00fa toku skuto\u010dn\u00fdch d\u00e1t , extr\u00e9mnym za\u0165a\u017een\u00edm cie\u013eov\u00e9ho procesora, alebo zahlten\u00edm pam\u00e4te.<\/li>\n<li>vlo\u017eenie chybn\u00fdch konfigura\u010dn\u00fdch inform\u00e1cii, napr. inform\u00e1cie o\u00a0smerovan\u00ed v\u00a0sieti<\/li>\n<li>naru\u0161enie stavu komunik\u00e1cie, teda nevy\u017eiadan\u00e9 resetovanie rel\u00e1cie TCP<\/li>\n<li>po\u0161kodenie fyzick\u00fdch sie\u0165ov\u00fdch komponentov<\/li>\n<li>prek\u00e1\u017eanie na komunika\u010dnom m\u00e9diu medzi ur\u010den\u00fdmi u\u017e\u00edvate\u013emi tak, \u017ee im znemo\u017en\u00ed adekv\u00e1tne komunikova\u0165<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h2>Syn-flood<\/h2>\n<hr \/>\n<h2><\/h2>\n<p>DoS \u00fatok typu SYN flood vyu\u017e\u00edva \u0161tandardn\u00fd, tzv. trojf\u00e1zov\u00fd handshaking (zah\u00e1jenie konverz\u00e1cie medzi po\u010d\u00edta\u010dmi). \u00dato\u010dn\u00edk po\u0161le na cie\u013eov\u00fd syst\u00e9m z\u00e1plavu TCP\/SYN paketov s\u00a0falo\u0161nou hlavi\u010dkou odosielate\u013ea. Ka\u017ed\u00fd z\u00a0t\u00fdchto falo\u0161n\u00fdch paketov mus\u00ed server prija\u0165 a\u00a0obsl\u00fa\u017ei\u0165 ako be\u017en\u00fa \u017eiados\u0165 o pripojenie. \u00a0A\u00a0\u010falej sa udalosti odohraj\u00fa takto:<\/p>\n<ul>\n<li>Na dan\u00fa slu\u017ebu alebo po\u010d\u00edta\u010d je poslan\u00fd SYN paket oznamuj\u00faci nadviazanie nov\u00e9ho TCP spojenia<\/li>\n<li>Prij\u00edmaj\u00faci po\u010d\u00edta\u010d potvrd\u00ed prijatie SYN paketu paketom SYN-ACK.<\/li>\n<li>N\u00e1sledne by mal nasledova\u0165 ACK paket od strany odosielate\u013ea, ten v\u0161ak v pr\u00edpade DoS \u00fatoku nikdy nedoraz\u00ed, preto\u017ee hlavi\u010dka odosielate\u013ee bola sfal\u0161ovan\u00e1. Takto polootvoren\u00e1 \u017eiados\u0165 ist\u00fa dobu blokuje ostatn\u00e9, legit\u00edmne \u017eiadosti o pripojenie.<\/li>\n<li>In\u00fdm negat\u00edvnym d\u00f4sledkom \u00fatoku SYN flood je, \u017ee prij\u00edmaj\u00faci po\u010d\u00edta\u010d v kr\u00e1tkom \u010dase zaznamen\u00e1 kritick\u00e9 mno\u017estvo nov\u00fdch po\u017eiadaviek na spojenie (SYN flood), ktor\u00e9 nie je schopn\u00fd obsl\u00fa\u017ei\u0165 z d\u00f4vodu prete\u010denia fronty nevybaven\u00fdch po\u017eiadaviek.<\/li>\n<\/ul>\n<p>Graficky by sa to dalo zn\u00e1zorni\u0165 asi takto:<\/p>\n<p><a href=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/SYN1.png?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"2179\" data-permalink=\"https:\/\/preventista.sk\/info\/spustite-siet-2-ked-sa-vam-sluzba-odoprie\/syn1\/\" data-orig-file=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/SYN1.png?fit=427%2C147&amp;ssl=1\" data-orig-size=\"427,147\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"SYN1\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/SYN1.png?fit=427%2C147&amp;ssl=1\" class=\"size-full wp-image-2179 alignleft\" src=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/SYN1.png?resize=427%2C147&#038;ssl=1\" alt=\"SynFlooding\" width=\"427\" height=\"147\" srcset=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/SYN1.png?w=427&amp;ssl=1 427w, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/SYN1.png?resize=320%2C110&amp;ssl=1 320w\" sizes=\"auto, (max-width: 427px) 100vw, 427px\" \/><\/a> <a href=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/SYN2.png?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"2180\" data-permalink=\"https:\/\/preventista.sk\/info\/spustite-siet-2-ked-sa-vam-sluzba-odoprie\/syn2\/\" data-orig-file=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/SYN2.png?fit=423%2C146&amp;ssl=1\" data-orig-size=\"423,146\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"SYN2\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/SYN2.png?fit=423%2C146&amp;ssl=1\" class=\"aligncenter size-full wp-image-2180\" src=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/SYN2.png?resize=423%2C146&#038;ssl=1\" alt=\"Synflooding2\" width=\"423\" height=\"146\" srcset=\"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/SYN2.png?w=423&amp;ssl=1 423w, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/SYN2.png?resize=320%2C110&amp;ssl=1 320w\" sizes=\"auto, (max-width: 423px) 100vw, 423px\" \/><\/a><\/p>\n<h2><\/h2>\n<h2>Ping of Death<\/h2>\n<hr \/>\n<h2><\/h2>\n<p>Jeden z\u00a0klasick\u00fdch DDoS \u00fatokov je naz\u00fdvan\u00fd <strong>Ping of Death<\/strong>. Tento \u00fatok je zalo\u017een\u00fd na zasielan\u00ed chybn\u00fdch PING spr\u00e1v.<\/p>\n<p>Spr\u00e1vne formulovan\u00e1 PING spr\u00e1va m\u00e1 d\u013a\u017eku 56 bytov alebo tie\u017e 84 bytov ke\u010f berieme v\u00a0\u00favahu aj IP hlavi\u010dku. V\u00a0minulosti mnoho opera\u010dn\u00fdch syst\u00e9mov nebolo schopn\u00fdch spracova\u0165 ping packet v\u00e4\u010d\u0161\u00ed ako je 65\u00a0535 bytov, \u010do je maxim\u00e1lna ve\u013ekos\u0165 packetu IPv4. Pri zlo\u017een\u00ed fragmentovan\u00e9ho packetu sa zistilo, \u017ee je chybn\u00fd a\u00a0pr\u00edli\u0161 ve\u013ek\u00fd, \u010do mohlo vies\u0165 k\u00a0zahlteniu bufferu zariadenia.<\/p>\n<p>V\u00a0dne\u0161nej dobe sa pou\u017e\u00edva jednoduch\u00fd ping flooding, teda vyslanie tak\u00e9ho ve\u013ek\u00e9ho mno\u017estva packetov, ktor\u00e9 nie je schopn\u00e9 zariadenie spracova\u0165.<\/p>\n<p>&nbsp;<\/p>\n<h2>Smurf Attack<\/h2>\n<hr \/>\n<h2><\/h2>\n<p>Tento \u00fatok m\u00f4\u017ee ma\u0165 devasta\u010dn\u00e9 \u00fa\u010dinky ako pre sie\u0165 obete, tak pre sie\u0165 sprostredkovate\u013ea.<\/p>\n<p>Smurf attack je \u00fatok hrubou silou priamo na IP protokol a\u00a0jeho broadcast funkciu. K\u00a0tomuto \u00fatoku sa vyu\u017e\u00edvaj\u00fa spr\u00e1vy ICMP.<\/p>\n<p>Tento \u00fatok je zalo\u017een\u00fd na jednoduchom princ\u00edpe, je to prakticky len smerovanie a\u00a0o\u00a0zvy\u0161ok sa postar\u00e1 IP protokol. Sklad\u00e1 sa z\u00a0piatich \u010dast\u00ed:<\/p>\n<ul>\n<li>\u00dato\u010dn\u00edk identifikuje IP adresu obete<\/li>\n<li>Je vybran\u00e1 sie\u0165 sprostredkovate\u013ea, ktor\u00e1 bude zosil\u0148ova\u0165 \u00fatok<\/li>\n<li>N\u00e1sledne je zaslan\u00e9 obrovsk\u00e9 mno\u017estvo ICMP packetov na broadcastov\u00e9 adresy sprostredkuj\u00facich str\u00e1nok. Tieto packety maj\u00fa ako cie\u013eov\u00fa adresu zadan\u00fa IP adresu obete<\/li>\n<li>Sprostredkovate\u013e doru\u010d\u00ed broadcastov\u00fa spr\u00e1vu na 2. vrstvu TCP\/IP modelu v\u00a0jeho podsieti<\/li>\n<li>Po\u010d\u00edta\u010de v\u00a0sieti sprostredkovate\u013ea odpovedaj\u00fa na sie\u0165 obete<\/li>\n<\/ul>\n<p>M\u00f4\u017ee to znie\u0165 primit\u00edvne a\u00a0m\u00f4\u017eete sa sami seba p\u00fdta\u0165, ako m\u00f4\u017ee jednoduch\u00fd ping zr\u00fati\u0165 cel\u00fa sie\u0165? Predstavme si, \u017ee \u00fato\u010dn\u00edk m\u00e1 k\u00a0dispoz\u00edcii pripojenie T-1 a\u00a0ICMP packety zasiela r\u00fdchlos\u0165ou 1 Mbps na sie\u0165 sprostredkovate\u013ea, ktor\u00fd m\u00e1 100 po\u010d\u00edta\u010dov. Stane sa teda to, \u017ee k\u00a0obeti je vyslan\u00e9 mno\u017estvo ICMP packetov r\u00fdchlos\u0165ou 100 Mpbs. \u00dato\u010dn\u00edk m\u00f4\u017ee takto posiela\u0165 ICMP packety dovtedy k\u00fdm je pripojen\u00fd k\u00a0sieti, alebo k\u00fdm sprostredkovate\u013e tieto packety preposiela. To u\u017e znie trochu v\u00e1\u017enej\u0161ie, nie?<\/p>\n<p>&nbsp;<\/p>\n<h1>Ako v\u0161eobecne zabr\u00e1ni\u0165 DDoS \u00fatokom?<\/h1>\n<hr \/>\n<h1><\/h1>\n<p>Bohu\u017eia\u013e pre jednotlivca neexistuj\u00fa \u017eiadne skuto\u010dne efekt\u00edvne sp\u00f4soby ako sa nesta\u0165 obe\u0165ou DDoS \u00fatoku, no m\u00f4\u017eete vykona\u0165 nieko\u013eko opatren\u00ed, aby si \u00fato\u010dn\u00edk vybral in\u00fd po\u010d\u00edta\u010d a\u00a0nie ten v\u00e1\u0161. Napr\u00edklad:<\/p>\n<ul>\n<li>Nain\u0161talujte si antiv\u00edrusov\u00fd syst\u00e9m. Prv\u00fdm predpokladom vyhnutia sa DoS \u00fatoku, alebo sp\u00f4sobenia DoS \u00fatoku in\u00fdm obetiam je, \u017ee V\u00e1\u0161 po\u010d\u00edta\u010d sa infiltr\u00e1ciou tr\u00f3jskym ko\u0148om nestane \u201ezombie\u201c po\u010d\u00edta\u010dom<\/li>\n<li>Zapnite si firewall a\u00a0nakonfigurujte si ho tak, aby prep\u00fa\u0161\u0165al len komunik\u00e1ciu, o\u00a0ktor\u00fa ste \u017eiadali, alebo ktor\u00fa ste posielali<\/li>\n<li>Aplikovanie emailov\u00fdch filtrov v\u00e1m m\u00f4\u017ee pom\u00f4c\u0165 redukova\u0165 nechcen\u00fa komunik\u00e1ciu<\/li>\n<\/ul>\n<p>Pre v\u00e4\u010d\u0161ie organiz\u00e1cie existuj\u00fa efekt\u00edvnej\u0161ie sp\u00f4soby obrany, no je potrebn\u00e9 zd\u00f4razni\u0165, \u017ee protiopatrenia nie je mo\u017en\u00e9 aplikova\u0165 plo\u0161ne a v\u017edy je potrebn\u00e9 prisp\u00f4sobi\u0165 sa aktu\u00e1lnej situ\u00e1cii. Z dostupn\u00fdch mo\u017enost\u00ed je mo\u017en\u00e9 aplikova\u0165 Load Balancing, Scrubbing, (\u010disti\u010dky prev\u00e1dzky, pomocou ktor\u00fdch sa oddel\u00ed v\u00e4\u010d\u0161ina \u0161kodlivej prev\u00e1dzky od korektnej sie\u0165ovej prev\u00e1dzky) RTBH (Remotely Triggered Black Hole Routing \/ Filtering), Prefix-listy (t.j. obmedzenie propag\u00e1cie AS),\u00a0 Access-listy, firewalling, resp. application firewalling at\u010f.<\/p>\n<p>Prostriedky technologickej ochrany vo\u010di DDoS je zvy\u010dajne potrebn\u00e9 vz\u00e1jomne kombinova\u0165 a princ\u00edpom \u201esecurity in depth\u201c zre\u0165azi\u0165 viacero met\u00f3d, pod\u013ea toho, ak\u00fd je vektor \u00fatoku, ak\u00fd je cie\u013e \u00fatoku, ak\u00e9 m\u00e1 charakteristick\u00e9 vlastnosti at\u010f. Sp\u00f4sob aplik\u00e1cie je z\u00e1visl\u00fd na architekt\u00fare siete, na st\u00e1vaj\u00facich prvkoch ochrany at\u010f.<\/p>\n<h2><\/h2>\n<p>&nbsp;<\/p>\n<h2>Ako zabr\u00e1ni\u0165 Smurf Attack \u00fatoku?<\/h2>\n<hr \/>\n<h2><\/h2>\n<ul>\n<li>Aplikujte pr\u00edstupov\u00e9 listy (access list) na odch\u00e1dzaj\u00face rozhranie v\u00e1\u0161ho smerova\u010da<\/li>\n<li>Pokia\u013e v\u00fdslovne nepotrebujete vyu\u017e\u00edva\u0165 broadcast, nevyu\u017e\u00edvajte ho. Zablokujte t\u00fato slu\u017ebu na ka\u017edom rozhran\u00ed v\u00e1\u0161ho smerova\u010da<\/li>\n<li>Pokia\u013e spravujete v\u00e4\u010d\u0161iu sie\u0165 s\u00a0nieko\u013ek\u00fdmi CISCO smerova\u010dmi, m\u00f4\u017eete vyu\u017ei\u0165 pr\u00edkaz <em>ip verify unicast reverse-path<\/em> , ktor\u00fd over\u00ed \u017ee existuje sp\u00e4tn\u00e1 cesta k\u00a0ICMP packetu, pokia\u013e neexistuje je tak\u00fdto packet zahoden\u00fd<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><em>Aby sme sa nezamerali len na temn\u00fa stranu sie\u0165ov\u00fdch \u00fatokov, v\u00a0\u010fal\u0161ej \u010dasti si pribl\u00ed\u017eime\u00a0jedno zo zariaden\u00ed, ktor\u00e9 sl\u00fa\u017ei na ochranu intern\u00fdch siet\u00ed mnoh\u00fdch spolo\u010dnost\u00ed.<\/em><\/p>\n<p>&nbsp;<\/p>\n<p>Prv\u00e1 \u010das\u0165 seri\u00e1lu:\u00a0<a title=\"\u201cSpustite sie\u0165!\u201d \u2013 bezpe\u010dnos\u0165 a in\u00e9 pojmy\" href=\"https:\/\/preventista.sk\/info\/spustite-siet-bezpecnost-a-ine-pojmy\/\" target=\"_blank\">\u201cSpustite sie\u0165!\u201d \u2013 bezpe\u010dnos\u0165 a in\u00e9 pojmy<\/a><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Tom\u00e1\u0161 Paulus<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>Vo\u013en\u00fd preklad \u010dl\u00e1nkov<\/p>\n<p><a href=\"http:\/\/www.omnisecu.com\/security\/distributed-denial-of-service-ddos-attack.php\">http:\/\/www.omnisecu.com\/security\/distributed-denial-of-service-ddos-attack.php<\/a><\/p>\n<p><a href=\"http:\/\/www.techrepublic.com\/article\/understanding-a-smurf-attack-is-the-first-step-toward-thwarting-one\/\">http:\/\/www.techrepublic.com\/article\/understanding-a-smurf-attack-is-the-first-step-toward-thwarting-one\/<\/a><\/p>\n<p><a href=\"https:\/\/www.us-cert.gov\/ncas\/tips\/ST04-015\">https:\/\/www.us-cert.gov\/ncas\/tips\/ST04-015<\/a><\/p>\n<p><a href=\"http:\/\/www.digitalattackmap.com\/understanding-ddos\/\">http:\/\/www.digitalattackmap.com\/understanding-ddos\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp; &#8222;Spustite sie\u0165! 2&#8220; &#8211;\u00a0Ke\u010f sa v\u00e1m slu\u017eba odoprie Prv\u00e1 \u010das\u0165 n\u00e1m stru\u010dne pribl\u00ed\u017eila problematiku sie\u0165ovej bezpe\u010dnosti a\u00a0s\u00a0\u0148ou s\u00favisiace \u00fatoky na 3 z\u00e1kladn\u00e9 piliere bezpe\u010dnosti \u2013 d\u00f4vernos\u0165, integrita, dostupnos\u0165. Nasleduj\u00faci \u010dl\u00e1nok n\u00e1m podrobne pribl\u00ed\u017ei \u00fatok vo\u010di dostupnosti\u00a0 (DoS, resp. DDoS) a\u00a0tie\u017e sp\u00f4soby ako sa pred t\u00fdmito \u00fatokmi chr\u00e1ni\u0165. &nbsp; DoS Pri \u00fatoku DoS \u2013 Denial [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":2187,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[4],"tags":[32,21],"class_list":["post-2143","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-itbezp","tag-bezpecnost","tag-ochrana"],"aioseo_notices":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/DDoS1.jpg?fit=700%2C300&ssl=1","jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":1724,"url":"https:\/\/preventista.sk\/info\/spustite-siet-bezpecnost-a-ine-pojmy\/","url_meta":{"origin":2143,"position":0},"title":"&#8222;Spustite sie\u0165!&#8220; &#8211; bezpe\u010dnos\u0165 a in\u00e9 pojmy","author":"T.Paulus","date":"2. janu\u00e1ra 2014","format":false,"excerpt":"Sie\u0165ov\u00e1 bezpe\u010dnos\u0165 \u00a0v skratke Sie\u0165ov\u00e1 bezpe\u010dnos\u0165 je jedn\u00fdm z\u00a0mnoh\u00fdch odborov informatiky. T\u00fdka sa zabezpe\u010denia sieti a\u00a0sie\u0165ov\u00fdch zariaden\u00ed. Zaober\u00e1 sa tie\u017e prevenciou a\u00a0kontrolou neopr\u00e1vnen\u00e9ho pr\u00edstupu alebo prevenciou odcudzenia d\u00e1t. Rie\u0161i tie\u017e napr\u00edklad poskytovanie nepretr\u017eitej slu\u017eby pre opr\u00e1vnen\u00fdch u\u017e\u00edvate\u013eov \u2013 s\u00a0\u010d\u00edm s\u00favis\u00ed aj zabezpe\u010denie proti r\u00f4znym sie\u0165ov\u00fdm \u00fatokom. A\u00a0pr\u00e1ve t\u00fdmi sa bude\u2026","rel":"","context":"V &quot;Bezpe\u010dnos\u0165&quot;","block_context":{"text":"Bezpe\u010dnos\u0165","link":"https:\/\/preventista.sk\/info\/category\/itbezp\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/01\/Networking.jpg?fit=1000%2C999&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/01\/Networking.jpg?fit=1000%2C999&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/01\/Networking.jpg?fit=1000%2C999&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/01\/Networking.jpg?fit=1000%2C999&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":2189,"url":"https:\/\/preventista.sk\/info\/spustite-siet-3-systemy-detekcie-a-prevencie-prieniku\/","url_meta":{"origin":2143,"position":1},"title":"\u201eSpustite sie\u0165! 3\u201c \u2013 Syst\u00e9my detekcie a prevencie prieniku","author":"T.Paulus","date":"29. j\u00fala 2014","format":false,"excerpt":"Spolo\u010dne s\u00a0ka\u017edodenn\u00fdm v\u00fdvojom nov\u00fdch sie\u0165ov\u00fdch technol\u00f3gi\u00ed vstupuj\u00fa do hry tie\u017e nov\u00e9 hrozby, ktor\u00e9 sa sna\u017eia tieto technol\u00f3gie po\u0161kodi\u0165. Dynamick\u00e1 povaha sie\u0165ov\u00fdch \u00fatokov si vy\u017eaduje dynamick\u00fa obranu hne\u010f na nieko\u013ek\u00fdch miestach. Syst\u00e9my pre spr\u00e1vu siete \u010dasto kr\u00e1t disponuj\u00fa mo\u017enos\u0165ou monitorovania sie\u0165ovej prev\u00e1dzky a\u00a0pod\u00e1vaj\u00fa tie\u017e jednotn\u00fd poh\u013ead do internej sie\u0165ovej infra\u0161trukt\u00fary, \u010do\u2026","rel":"","context":"V &quot;Bezpe\u010dnos\u0165&quot;","block_context":{"text":"Bezpe\u010dnos\u0165","link":"https:\/\/preventista.sk\/info\/category\/itbezp\/"},"img":{"alt_text":"spustite siet 3 cover","src":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/spustite-siet-3-cover.jpg?fit=700%2C400&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/spustite-siet-3-cover.jpg?fit=700%2C400&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/spustite-siet-3-cover.jpg?fit=700%2C400&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2014\/07\/spustite-siet-3-cover.jpg?fit=700%2C400&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":775,"url":"https:\/\/preventista.sk\/info\/bezpecna-siet-wi-fi\/","url_meta":{"origin":2143,"position":2},"title":"Bezpe\u010dn\u00e1 sie\u0165 Wi-Fi","author":"T.Paulus","date":"31. j\u00fala 2013","format":false,"excerpt":"Je va\u0161a dom\u00e1ca bezdr\u00f4tov\u00e1 sie\u0165 bezpe\u010dn\u00e1? V\u00a0dne\u0161nej dobe plnej smartf\u00f3nov, tabletov a\u00a0kadejak\u00fdch in\u00fdch \u2013ov si u\u017e nedok\u00e1\u017eeme predstavi\u0165 \u017eivot bez pripojenia na internet. \u010casy, kedy ste museli na pripojenie \u010daka\u0165 5 min\u00fat a\u00a0popri tom ste po\u010d\u00favali kr\u00e1snu symf\u00f3niu zvukov V\u00e1\u0161ho modemu s\u00fa u\u017e d\u00e1vno za nami. Vo v\u00e4\u010d\u0161ine pr\u00edpadov je\u2026","rel":"","context":"V &quot;Bezpe\u010dnos\u0165&quot;","block_context":{"text":"Bezpe\u010dnos\u0165","link":"https:\/\/preventista.sk\/info\/category\/itbezp\/"},"img":{"alt_text":"bezpecna-wifi","src":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2013\/07\/bezpecna-wifi.jpg?fit=700%2C400&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2013\/07\/bezpecna-wifi.jpg?fit=700%2C400&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2013\/07\/bezpecna-wifi.jpg?fit=700%2C400&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2013\/07\/bezpecna-wifi.jpg?fit=700%2C400&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":2440,"url":"https:\/\/preventista.sk\/info\/ako-hacknut-e-banku\/","url_meta":{"origin":2143,"position":3},"title":"Ako \u201ehackn\u00fa\u0165\u201c e-banku?","author":"I. Makatura","date":"17. janu\u00e1ra 2015","format":false,"excerpt":"Alebo, ako pou\u017e\u00edva\u0165 e-banku a nesta\u0165 sa obe\u0165ou podvodn\u00edkov Ako som u\u017e uviedol v inom \u010dl\u00e1nku, v dne\u0161nej dobe sa za vlastn\u00edctvo, okrem hmotn\u00fdch statkov,\u00a0 pova\u017euj\u00fa aj nehmotn\u00e9 statky a\u00a0pr\u00e1va. V\u00a0digit\u00e1lnej \u00e9re\u00a0 s\u00fa to \u0161pecificky tzv. \u00a0\u201cinforma\u010dn\u00e9 akt\u00edva\u201d. Ak sa \u010das od \u010dasu vyskytla snaha podvodn\u00edkov z\u00edska\u0165 finan\u010dn\u00fd prospech z\u00a0informa\u010dn\u00fdch\u2026","rel":"","context":"V &quot;Bezpe\u010dnos\u0165&quot;","block_context":{"text":"Bezpe\u010dnos\u0165","link":"https:\/\/preventista.sk\/info\/category\/itbezp\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2015\/01\/Ebanka.jpg?fit=700%2C400&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2015\/01\/Ebanka.jpg?fit=700%2C400&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2015\/01\/Ebanka.jpg?fit=700%2C400&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2015\/01\/Ebanka.jpg?fit=700%2C400&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":1306,"url":"https:\/\/preventista.sk\/info\/techniky-socialneho-inzinierstva\/","url_meta":{"origin":2143,"position":4},"title":"Techniky soci\u00e1lneho in\u017einierstva  II.","author":"T.Paulus","date":"8. septembra 2013","format":false,"excerpt":"Techniky soci\u00e1lneho in\u017einierstva \u201eZlat\u00e9 pravidlo ako sa nenecha\u0165 oklama\u0165 \u2013 Ak je nie\u010do pr\u00edli\u0161 dobr\u00e9 na to, aby to bola pravda, tak to pravda nie je.\u201c \u00a0 Bez zbyto\u010dn\u00e9ho chodenia okolo hor\u00facej ka\u0161e priamo nadvia\u017eem na \u010dl\u00e1nok \u201eSoci\u00e1lne in\u017einierstvo-nech\u00e1te sa nachyta\u0165?\u201c. Vysvetlili sme si z\u00e1kladn\u00e9 princ\u00edpy soci\u00e1lneho hackingu a\u00a0dnes v\u00e1m\u2026","rel":"","context":"V &quot;Bezpe\u010dnos\u0165&quot;","block_context":{"text":"Bezpe\u010dnos\u0165","link":"https:\/\/preventista.sk\/info\/category\/itbezp\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2013\/09\/phishing_11.jpeg?fit=525%2C358&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2013\/09\/phishing_11.jpeg?fit=525%2C358&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2013\/09\/phishing_11.jpeg?fit=525%2C358&ssl=1&resize=525%2C300 1.5x"},"classes":[]},{"id":2583,"url":"https:\/\/preventista.sk\/info\/bezpecne-hranice-cast-1-co-je-to-penetracny-test\/","url_meta":{"origin":2143,"position":5},"title":"Bezpe\u010dn\u00e9 hranice  \u010cas\u0165 1: \u010co je to penetra\u010dn\u00fd test","author":"I. Makatura","date":"16. febru\u00e1ra 2015","format":false,"excerpt":"V\u00fdraz \u201eperimeter\u201c v\u00a0matematike znamen\u00e1 celkov\u00fa d\u013a\u017eku vonkaj\u0161ieho obvodu dvojrozmern\u00e9ho objektu. V\u00a0prenesenom zmysle sa tento v\u00fdraz pou\u017e\u00edva ako \u201ehranica\u201c, teda priestor, ktor\u00fd sa nach\u00e1dza na vonkaj\u0161ej strane hranice vymedzen\u00e9ho objektu. V\u00a0informa\u010dnej bezpe\u010dnosti sa pod pojmom \u201eperimeter\u201c rozumie vonkaj\u0161\u00ed, cudz\u00ed priestor, mimo predmetn\u00e9ho virtu\u00e1lneho prostredia. Naj\u010dastej\u0161ie sa v\u00a0tomto kontexte jedn\u00e1 o\u00a0sie\u0165ov\u00fd perimeter,\u2026","rel":"","context":"V &quot;Bezpe\u010dnos\u0165&quot;","block_context":{"text":"Bezpe\u010dnos\u0165","link":"https:\/\/preventista.sk\/info\/category\/itbezp\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2015\/02\/hranice-1.jpg?fit=700%2C400&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2015\/02\/hranice-1.jpg?fit=700%2C400&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2015\/02\/hranice-1.jpg?fit=700%2C400&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/preventista.sk\/info\/wp-content\/uploads\/2015\/02\/hranice-1.jpg?fit=700%2C400&ssl=1&resize=700%2C400 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/preventista.sk\/info\/wp-json\/wp\/v2\/posts\/2143","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/preventista.sk\/info\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/preventista.sk\/info\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/preventista.sk\/info\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/preventista.sk\/info\/wp-json\/wp\/v2\/comments?post=2143"}],"version-history":[{"count":36,"href":"https:\/\/preventista.sk\/info\/wp-json\/wp\/v2\/posts\/2143\/revisions"}],"predecessor-version":[{"id":2186,"href":"https:\/\/preventista.sk\/info\/wp-json\/wp\/v2\/posts\/2143\/revisions\/2186"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/preventista.sk\/info\/wp-json\/wp\/v2\/media\/2187"}],"wp:attachment":[{"href":"https:\/\/preventista.sk\/info\/wp-json\/wp\/v2\/media?parent=2143"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/preventista.sk\/info\/wp-json\/wp\/v2\/categories?post=2143"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/preventista.sk\/info\/wp-json\/wp\/v2\/tags?post=2143"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}