AmaTrojans asetshenziselwa ukuqalisa ukuhlaselwa kwe-Distributed Denial of Service (DDoS) ngokumelene nezinhlelo ezihlosiwe, kodwa yini nje ukuhlasela kweDDoS futhi kwenziwa kanjani?
Ezingeni layo eliyisisekelo, ukuhlaselwa kwe-Distributed Denial of Service (DDoS) kugxila ohlelweni olubhekiswe kulolu datha, njengokuthi impendulo evela ohlelweni olubhekiswe kuyo inganciphisa noma imiswe ngokuphelele. Ukuze udale inani elidingekayo lomgwaqo, inethiwekhi ye-zombie noma ikhompyutha ye-bot isetshenziswa kaningi.
Ama-Zombies noma ama-botnets amakhompyutha ahlehlisiwe ngabahlaseli, ngokuvamile ngokusetshenziswa kweTrojans, okuvumela lezi zinhlelo ezilahlekile zilawulwe kude. Ngokubambisana, lezi zinhlelo zisebenziselwa ukudala ukugeleza kwe-traffic edingekayo ukudala ukuhlasela kweDDoS.
Ukusetshenziswa kwalawa mabhodlela kuvame ukuthengiswa futhi kuhwetshwe phakathi kwabahlaseli, ngakho-ke uhlelo oluhlehlisiwe lungaphansi kokulawulwa kwezigebengu eziningi - ngayinye enenhloso ehlukile engqondweni. Abanye abahlaseli bangasebenzisa i-botnet njenge-spam-relay, abanye basebenze njenge-site yokulanda ikhodi enonya, abanye babambe imikhonyovu yokuphanga, nabanye ukuhlaselwa kweDDoS okubalulwe ngenhla.
Amasu amaningana angasetshenziselwa ukusiza ukuhlaselwa kwe-Distributed Denial of Service. Okubili kokujwayelekile kuvame izicelo ze-HTTP GET nezikhukhula ze-SYN. Esinye sezibonelo ezidume kakhulu ze-HTTP GET isisulu sasivela kumbungu we-MyDoom, ohlose iwebhusayithi ye-SCO.com. Ukuhlasela kwe-GET kusebenza njengoba igama layo liphakamisa - lithumela isicelo sekhasi elithile (ngokuvamile ikhasi lasekhaya) kuseva eliqondisiwe. Endabeni ye- MyDoom worm , izicelo ezingu-64 zithunyelwe njalo ngomzuzwana kuzo zonke izinhlelo zokutheleleka . Njengoba amashumi ezinkulungwane zamakhompiyutha acatshangwa ukuthi anegciwane le-MyDoom, ukuhlaselwa ngokushesha kwafakazela kakhulu i-SCO.com, ukuyiqhaqhaza ungaxhunyiwe ku-intanethi izinsuku ezimbalwa.
Isikhukhula se-SYN ngokuyisisekelo siyisandla sokukhishwa kwesandla. Ukuxhumana kwe-intanethi isebenzisa ukuxhunyanwa ngezindlela ezintathu. Iklayenti yokuqalisa iqalisa nge-SYN, iseva iyaphendula nge-SYN-ACK, futhi iklayenti kufanele iphendule nge-ACK. Ukusebenzisa amakheli we-IP angenayo, umhlaseli uthumela i-SYN eholela ku-SYN-ACK ithunyelwa ekhelini elingelona elicelayo (futhi elingajwayelekile). Iseva ilinda ukuthi impendulo ye-ACK ayitholakali. Uma izinombolo ezinkulu zalawa maphakethe we-SYN aphelelwe yisizathu, izinsiza ze-server ziphelile futhi iseva iyancipha kwi-SYN Flood DDoS.
Ezinye izinhlobo eziningi zokuhlaselwa kwe-DDoS zingasungulwa, kuhlanganise nokuhlaselwa kwe-UDP Fragment, Izikhukhula ze-ICMP, ne-Ping of Death. Ukuze uthole imininingwane eyengeziwe mayelana nezinhlobo zokuhlaselwa kwe-DDoS, vakashela i-Advanced Networking Management Lab (ANML) futhi ubuyekeze izinsizakalo zabo zokusabalalisa ze-Distributed Denial of Service (DDoS).
Bheka futhi: Ingabe i-PC yakho i-zombie?