{"id":5448,"date":"2025-03-18T14:23:08","date_gmt":"2025-03-18T13:23:08","guid":{"rendered":"https:\/\/www.websupport.cz\/blog\/?p=5448"},"modified":"2025-06-11T16:34:28","modified_gmt":"2025-06-11T14:34:28","slug":"co-je-to-ddos-utok-a-jak-se-mu-ucinne-branit","status":"publish","type":"post","link":"https:\/\/www.websupport.cz\/blog\/2025\/03\/co-je-to-ddos-utok-a-jak-se-mu-ucinne-branit\/","title":{"rendered":"Co je to DDoS \u00fatok a jak se mu \u00fa\u010dinn\u011b br\u00e1nit? (+p\u0159\u00edklady)"},"content":{"rendered":"\n

V\u00edte, v \u010dem spo\u010d\u00edv\u00e1 DDoS \u00fatok a jak\u00fd je rozd\u00edl mezi DDoS a DoS? Pokud m\u00e1te vlastn\u00ed web nebo e-shop, ur\u010dit\u011b \u010dt\u011bte d\u00e1l!<\/p>\n\n\n\n

DoS \u00fatok \u2013 co to je?<\/h2>\n\n\n\n

DoS je zkratkou pro Denial of Service, v p\u0159ekladu odep\u0159en\u00ed slu\u017eby, co\u017e je c\u00edlem tohoto kybernetick\u00e9ho \u00fatoku. Napaden\u00e1 slu\u017eba v tomto p\u0159\u00edpad\u011b m\u016f\u017ee b\u00fdt jak\u00e1koliv webov\u00e1 str\u00e1nka nebo aplikace, ale i cel\u00e1 firemn\u00ed s\u00ed\u0165.<\/p>\n\n\n\n

Tento \u00fatok je \u201ejednodu\u0161\u0161\u00ed verze\u201c DDoS. Spo\u010d\u00edv\u00e1 v tom, \u017ee \u00fato\u010dn\u00edk pou\u017eije jedno za\u0159\u00edzen\u00ed k \u00fatok\u016fm na jin\u00e9 za\u0159\u00edzen\u00ed tak, aby p\u0159estalo \u0159\u00e1dn\u011b fungovat.<\/p>\n\n\n\n

P\u0159\u00edklad<\/strong><\/h4>\n\n\n\n

Pokud se v\u00e1m to zd\u00e1 p\u0159\u00edli\u0161 abstraktn\u00ed, p\u0159edstavte si t\u0159eba web katastru nemovitost\u00ed. Pokud vyu\u017eijete jedno za\u0159\u00edzen\u00ed, nap\u0159\u00edklad sv\u016fj po\u010d\u00edta\u010d, ze kter\u00e9ho d\u00edky speci\u00e1ln\u011b vyvinut\u00e9mu programu vy\u0161lete za sekundu des\u00edtky a\u017e stovky po\u017eadavk\u016f na vyhled\u00e1n\u00ed nemovitost\u00ed, co ud\u011bl\u00e1 server, na kter\u00e9m katastr b\u011b\u017e\u00ed? P\u0159estane b\u00fdt schopen tyto po\u017eadavky vy\u0159izovat kv\u016fli \u00fapln\u00e9mu zahlcen\u00ed pam\u011bti a v\u00fdpo\u010detn\u00edho v\u00fdkonu.<\/p>\n\n\n\n

V\u00fdsledkem m\u016f\u017ee b\u00fdt pomal\u00e9 na\u010d\u00edt\u00e1n\u00ed slu\u017eby nebo jej\u00ed \u00fapln\u00e9 \u201espadnut\u00ed\u201c. Na mohutnosti \u00fatoku z\u00e1le\u017e\u00ed, zda toto omezen\u00ed bude trvat n\u011bkolik minut, hodin, dn\u016f nebo i d\u00e9le. Pokud m\u00e1te nap\u0159\u00edklad vlastn\u00ed e-shop, asi u\u017e v\u00e1m za\u010d\u00ednaj\u00ed blikat kontrolky.<\/p>\n\n\n\n

Co je DDoS \u00fatok?<\/h2>\n\n\n\n

P\u0159i DDoS \u00fatoku je c\u00edl \u00fatoku stejn\u00fd jako u DoS, li\u0161\u00ed se v\u0161ak zp\u016fsobem jeho realizace. Jak u\u017e napov\u00edd\u00e1 v\u00fdznam t\u00e9to zkratky \u2013 Distributed Denial of Service (v p\u0159ekladu distribuovan\u00e9 odep\u0159en\u00ed slu\u017eby), \u00fato\u010dn\u00edk se v prvn\u00edm kroku nezam\u011b\u0159uje p\u0159\u00edmo na za\u0159\u00edzen\u00ed ob\u011bti. Nejprve si postupn\u011b vytv\u00e1\u0159\u00ed \u201earm\u00e1du\u201c po\u010d\u00edta\u010d\u016f, kter\u00e1 mu n\u00e1sledn\u011b poslou\u017e\u00ed k samotn\u00e9mu \u00fatoku.<\/p>\n\n\n\n

Jak?<\/strong> \u00dato\u010dn\u00edk si vytipuje jin\u00e1 za\u0159\u00edzen\u00ed (nej\u010dast\u011bji po\u010d\u00edta\u010de propojen\u00e9 internetem nebo r\u016fzn\u00e1 IoT za\u0159\u00edzen\u00ed, kter\u00e1 zn\u00e1me i pod pojmem chytr\u00e1 za\u0159\u00edzen\u00ed p\u0159ipojen\u00e1 k internetu), kter\u00e1 z \u0159\u00eddic\u00edho serveru nakaz\u00ed virem a ud\u011bl\u00e1 z nich tzv. boty nebo zombie za\u0159\u00edzen\u00ed.<\/p>\n\n\n\n

Jak je nakaz\u00ed?<\/strong> Zp\u016fsob\u016f je mnoho. Jedn\u00edm z nich m\u016f\u017ee b\u00fdt klasick\u00fd phishing, o kter\u00e9m si u n\u00e1s m\u016f\u017eete p\u0159e\u010d\u00edst v n\u011bkter\u00e9m ze star\u0161\u00edch \u010dl\u00e1nk\u016f<\/a>.<\/p>\n\n\n\n

Takto infikovan\u00fdm zomb\u00edk\u016fm \u00fato\u010dn\u00edk n\u00e1sledn\u011b rozes\u00edl\u00e1 p\u0159\u00edkazy, co maj\u00ed d\u011blat. P\u0159\u00edkazy spo\u010d\u00edvaj\u00ed pr\u00e1v\u011b v \u00fatoc\u00edch na c\u00edlov\u00e9 za\u0159\u00edzen\u00ed p\u0159\u00edmo z t\u011bchto infikovan\u00fdch po\u010d\u00edta\u010d\u016f, a to dokonce a\u017e v objemu 5,6 Tbps (terabit\u016f za sekundu). Takto se vy\u0161le nadm\u011brn\u00fd po\u010det po\u017eadavk\u016f na c\u00edlov\u00e9 za\u0159\u00edzen\u00ed ne z jednoho po\u010d\u00edta\u010de, ale z cel\u00e9 s\u00edt\u011b, kter\u00e1 tvo\u0159\u00ed tzv. botnet (s\u00ed\u0165 infikovan\u00fdch \u201ezombie\u201c po\u010d\u00edta\u010d\u016f).<\/p>\n\n\n\n

Takov\u00fd botnet je mo\u017en\u00e9 si na dark webu i b\u011b\u017en\u011b pronajmout, a to za relativn\u011b n\u00edzk\u00e9 ceny.<\/p>\n\n\n\n

P\u0159\u00edklad<\/strong><\/h4>\n\n\n\n

V\u011bt\u0161ina HTTP DDoS \u00fatok\u016f v roce 2024 (73 %) byla uskute\u010dn\u011bna ze zn\u00e1m\u00fdch botnet\u016f (zdroj: cloudflare.com).<\/p>\n\n\n\n

P\u0159edstavme si to jako 100 hacker\u016f, kte\u0159\u00ed sed\u00ed za sv\u00fdmi po\u010d\u00edta\u010di na r\u016fzn\u00fdch m\u00edstech, ve stejn\u00e9m \u010dase se koordinuj\u00ed a vys\u00edlaj\u00ed po\u017eadavky na c\u00edlov\u00e9 za\u0159\u00edzen\u00ed, aby ochromili jeho \u010dinnost. Jen\u017ee tito hacke\u0159i nejsou \u017eiv\u00ed, ale nahrazuje je s\u00ed\u0165 po\u010d\u00edta\u010d\u016f \u0159\u00edzen\u00fdch z jednoho centra.<\/p>\n\n\n\n

Ve v\u00fdsledku to m\u00e1me jako d\u00e1lnici, kterou ucpalo mno\u017estv\u00ed aut z r\u016fzn\u00fdch sm\u011br\u016f. A lid\u00e9, kte\u0159\u00ed se pot\u0159ebuj\u00ed dostat do pr\u00e1ce, nemohou projet. V p\u0159\u00edpad\u011b DDoS \u00fatoku je cesta ucpan\u00e1 z\u00e1m\u011brn\u011b.<\/p>\n\n\n\n

Co pot\u0159ebuje \u00fato\u010dn\u00edk?<\/h2>\n\n\n\n