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4. firewall, ma hoa, virus

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Quoc Nguyen
Quoc Nguyen

4. firewall, ma hoa, virus

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T??ng l?a (Firewall) n T??ng l?a l¨¤ g¨¬? L¨¤ m?t h¨¤ng r¨¤o gi?a hai m?ng m¨¢y t¨ªnh - n¨® b?o v? m?ng n¨¤y tr¨¢nh kh?i s? x?m nh?p t? m?ng kh¨¢c
n C¨¢c th? h? t??ng l?a n T??ng l?a l?c g¨®i tin : c?ng ngh? t??ng l?a th? h? ??u ti¨ºn ph?n t¨ªch l?u l??ng m?ng ? t?ng v?n chuy?n (transport protocol layer) . n T??ng l?a m?c giao v?n (circuit level firewall) : c?ng ngh? t??ng l?a th? h? th? 2 cho ph¨¦p x¨¢c ??nh m?t g¨®i tin c¨® th? l¨¤ m?t y¨ºu c?u k?t n?i, m?t g¨®i d? li?u thu?c m?t k?t n?i ho?c l¨¤ m?t m?ch ?o (virtual circuit) ? t?ng giao v?n gi?a 2 m¨¢y
n T??ng l?a m?c ?ng d?ng : c?ng ngh? t??ng l?a th? h? th? 3, n¨® ki?m tra t¨ªnh ?¨²ng ??n d? li?u thu?c t?ng ?ng d?ng trong c¨¢c g¨®i tin tr??c khi cho ph¨¦p k?t n?i. Ngo¨¤i ra, n¨® c¨°n ki?m tra t¨ªnh h?p l? c?a c¨¢c th?ng s? b?o m?t kh¨¢c ch? c¨® ? t?ng ?ng d?ng nh? l¨¤ m?t kh?u ng??i d¨´ng v¨¤ c¨¢c y¨ºu c?u d?ch v?.
n T??ng l?a l?c g¨®i tin ??ng : c?ng ngh? t??ng l?a th? h? th? t?. N¨® r?t h?u ¨ªch ??i v?i giao th?c UDP.
n So s¨¢nh gi?a t?c ?? v¨¤ hi?u qu? b?o m?t : n C¨¢c t??ng l?a l?c g¨®i tin n¨®i chung c¨® t?c ?? nhanh nh?t sau ?¨® l¨¤ t??ng l?a m?c giao v?n, t??ng l?a l?c g¨®i tin ??ng v¨¤ t??ng l?a m?c ?ng d?ng n M?c ?? ki?m tra b?o m?t n¨®i chung l?i theo h??ng ng??c l?i, g¨®i tin c¨¤ng qua nhi?u t?ng th¨¬ n¨® c¨¤ng ph?i ???c ki?m tra chi ti?t h?n
n So s¨¢nh t??ng l?a c?a c¨¢c h?ng n?i ti?ng Check Point, NetScreen v¨¤ Cisco
Kh? n?ng ng?n ch?n t?n c?ng (Attack Prevention Capabilities)
Kh? n?ng h? tr? c¨¢c ?ng d?ng/giao th?c
M? H?A n M? h¨®a : l¨¤m cho d? li?u kh?ng th? ??c ???c khi b? l?y tr?m. n C¨¢c ph??ng ph¨¢p m? h¨®a: n M? h¨®a ??i x?ng: d¨´ng c¨´ng m?t key cho m? h¨®a v¨¤ gi?i m?
n M? h¨®a pulic key :
n Message Authentication Code :
n Ch? k? ?i?n t? (Digital signature) :
VIRUS n Virus tr¨ºn m¨¢y t¨ªnh l¨¤ m?t ch??ng tr¨¬nh nh? l¨¤m thay ??i ho?t ??ng c?a m¨¢y t¨ªnh ngo¨¤i s? ki?m so¨¢t c?a ng??i s? d?ng . n C¨¢c lo?i Virus : n Virus tr¨ºn files : C¨¢c Virus lo?i file th??ng l?y v¨¤o c¨¢c t?p ch??ng tr¨¬nh nh? c¨¢c t?p .com v¨¤ .exe
n Virus tr¨ºn Boot sector : Virus c¨® th? l?y nhi?m v¨¤o c¨¢c Boot sector c?a ? ??a c?ng ho?c ? ??a m?m n?i ch?a c¨¢c ch??ng tr¨¬nh kh?i ??ng. n Virus tr¨ºn Master Boot Record : V? c? b?n d?ng virus n¨¤y c?ng nh? Virus tr¨ºn Boostector nh?ng n?i l?y nhi?m l¨¤ master boot record
n Macro virus : ??y l¨¤ lo?i virus l?y tr¨ºn c¨¢c t?p d? li?u. C¨¢c ?o?n m? code c?a Virus tr¨ºn c¨¢c m? Visual Basic trong c¨¢c t?p Exel, MS word, MS Access, MS Poiwer point¡­ c¨® th? g?y l?y nhi?m Virus t?i c¨¢c t?p d? li?u ho?c t?p ch??ng tr¨¬nh kh¨¢c. Do vi?c x?y d?ng m?t ?o?n ch??ng tr¨¬nh macro
n Virus hoax : L¨¤ c¨¢c th? ?i?n t? (E-mail) c¨® ch?a c¨¢c ?o?n ch??ng tr¨¬nh khi m? c¨¢c th? n¨¤y c¨¢c virus s? l?y v¨¤o m¨¢y t¨ªnh c?a ng??i s? d?ng v¨¤ s? th?c hi?n c¨¢c ch?c n?ng kh?ng ki?m so¨¢t ???c nh? l?y tr?m ??a ch?, g?i c¨¢c th? c¨® c¨¢c files th?ng tin tr¨ºn m¨¢y t¨ªnh c?a ng??i s? d?ng th?m ch¨ª xo¨¢ c¨¢c c¨¢c th?ng tin tr¨ºn ? ??a c?a m¨¢y t¨ªnh¡­,
n Virus ¡°Con ng?a th¨¤nh T?-roa¡± : ??y l¨¤ lo?i virus kh¨¢ nguy hi?m l¨¤m thay ??i s? li?u, l?y c?p c¨¢c th?ng tin tr¨ºn m¨¢y t¨ªnh¡­ n¨® th??ng c¨® d?ng m?t file ???c g?i k¨¨m theo e-mail. n Virus h?n h?p : lo?i virus c¨® t?t c? c¨¢c t¨ªnh n?ng l?y nhi?m v¨¤ ph¨¢ ho?i tr¨ºn c? c¨¢c t?p, hay boot record. ??y l¨¤ lo?i virus tr¨ºn c¨¢c kh¨® di?t do ho?t ??ng ??ng th?i tr¨ºn nhi?u lo?i m?i tr??ng.
n C¨¢c k? thu?t s? d?ng trong virus : n Th??ng tr¨² n ?n th?n (Stealth) n Bi?n h¨¬nh (Polymorphic)
n C¨¢c ???ng th?m nh?p virus v¨¤o h? th?ng m¨¢y t¨ªnh : n Qua ng??i s? d?ng m¨¢y t¨ªnh n Qua h? th?ng th? ?i?n t? (E-mail) n Qua c¨¢c d?ch v? Internet
ANTI-VIRUS n H? th?ng ph¨°ng ch?ng Virus s? ti?n h¨¤nh theo m? h¨¬nh hai l?p: Ch?ng Virus v¨¤ ph¨°ng Virus n Ph¨°ng virus : ng?n ch?n s? th?m nh?p c?a Virus qua c¨¢c ???ng l?y nhi?m ?? n¨ºu ? tr¨ºn nh? qua li¨ºn k?t Internet, mail¡­.. n Ch?ng virus : C?p nh?t v¨¤ c¨¤i ??t c¨¢c ph?n m?m ch?ng Virus m?i nh?t
n C¨¢c quy tr¨¬nh b?o v? m¨¢y t¨ªnh : n ??ng k? : M¨¢y t¨ªnh ???c ??ng k? s? ???c nh¨®m ch?ng Virus m¨¢y t¨ªnh ??a v¨¤o danh s¨¢ch qu?n l? n C¨¤i ??t ph?n m?m ch?ng virus n Ph¨°ng ch?ng Virus m¨¢y t¨ªnh ??nh k? n Di?t Virus m¨¢y t¨ªnh trong c¨¢c tru¨°ng h?p b?t th??ng
n Ch?ng Virus m¨¢y t¨ªnh th?m nh?p qua c?ng Internet : cho m¨¢y ch? di?t Virus m¨¢y t¨ªnh t?i c?ng Internet . n Ch?ng Virus m¨¢y t¨ªnh th?m nh?p qua th? ?i?n t? : cho m¨¢y ch? di?t Virus m¨¢y t¨ªnh t?i c¨¢c mail server
THANKS

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4. firewall, ma hoa, virus

  • 1. T??ng l?a (Firewall) n T??ng l?a l¨¤ g¨¬? L¨¤ m?t h¨¤ng r¨¤o gi?a hai m?ng m¨¢y t¨ªnh - n¨® b?o v? m?ng n¨¤y tr¨¢nh kh?i s? x?m nh?p t? m?ng kh¨¢c
  • 2. n C¨¢c th? h? t??ng l?a n T??ng l?a l?c g¨®i tin : c?ng ngh? t??ng l?a th? h? ??u ti¨ºn ph?n t¨ªch l?u l??ng m?ng ? t?ng v?n chuy?n (transport protocol layer) . n T??ng l?a m?c giao v?n (circuit level firewall) : c?ng ngh? t??ng l?a th? h? th? 2 cho ph¨¦p x¨¢c ??nh m?t g¨®i tin c¨® th? l¨¤ m?t y¨ºu c?u k?t n?i, m?t g¨®i d? li?u thu?c m?t k?t n?i ho?c l¨¤ m?t m?ch ?o (virtual circuit) ? t?ng giao v?n gi?a 2 m¨¢y
  • 3. n T??ng l?a m?c ?ng d?ng : c?ng ngh? t??ng l?a th? h? th? 3, n¨® ki?m tra t¨ªnh ?¨²ng ??n d? li?u thu?c t?ng ?ng d?ng trong c¨¢c g¨®i tin tr??c khi cho ph¨¦p k?t n?i. Ngo¨¤i ra, n¨® c¨°n ki?m tra t¨ªnh h?p l? c?a c¨¢c th?ng s? b?o m?t kh¨¢c ch? c¨® ? t?ng ?ng d?ng nh? l¨¤ m?t kh?u ng??i d¨´ng v¨¤ c¨¢c y¨ºu c?u d?ch v?.
  • 4. n T??ng l?a l?c g¨®i tin ??ng : c?ng ngh? t??ng l?a th? h? th? t?. N¨® r?t h?u ¨ªch ??i v?i giao th?c UDP.
  • 5. n So s¨¢nh gi?a t?c ?? v¨¤ hi?u qu? b?o m?t : n C¨¢c t??ng l?a l?c g¨®i tin n¨®i chung c¨® t?c ?? nhanh nh?t sau ?¨® l¨¤ t??ng l?a m?c giao v?n, t??ng l?a l?c g¨®i tin ??ng v¨¤ t??ng l?a m?c ?ng d?ng n M?c ?? ki?m tra b?o m?t n¨®i chung l?i theo h??ng ng??c l?i, g¨®i tin c¨¤ng qua nhi?u t?ng th¨¬ n¨® c¨¤ng ph?i ???c ki?m tra chi ti?t h?n
  • 6. n So s¨¢nh t??ng l?a c?a c¨¢c h?ng n?i ti?ng Check Point, NetScreen v¨¤ Cisco
  • 7. Kh? n?ng ng?n ch?n t?n c?ng (Attack Prevention Capabilities)
  • 8. Kh? n?ng h? tr? c¨¢c ?ng d?ng/giao th?c
  • 9. M? H?A n M? h¨®a : l¨¤m cho d? li?u kh?ng th? ??c ???c khi b? l?y tr?m. n C¨¢c ph??ng ph¨¢p m? h¨®a: n M? h¨®a ??i x?ng: d¨´ng c¨´ng m?t key cho m? h¨®a v¨¤ gi?i m?
  • 10. n M? h¨®a pulic key :
  • 12. n Ch? k? ?i?n t? (Digital signature) :
  • 13. VIRUS n Virus tr¨ºn m¨¢y t¨ªnh l¨¤ m?t ch??ng tr¨¬nh nh? l¨¤m thay ??i ho?t ??ng c?a m¨¢y t¨ªnh ngo¨¤i s? ki?m so¨¢t c?a ng??i s? d?ng . n C¨¢c lo?i Virus : n Virus tr¨ºn files : C¨¢c Virus lo?i file th??ng l?y v¨¤o c¨¢c t?p ch??ng tr¨¬nh nh? c¨¢c t?p .com v¨¤ .exe
  • 14. n Virus tr¨ºn Boot sector : Virus c¨® th? l?y nhi?m v¨¤o c¨¢c Boot sector c?a ? ??a c?ng ho?c ? ??a m?m n?i ch?a c¨¢c ch??ng tr¨¬nh kh?i ??ng. n Virus tr¨ºn Master Boot Record : V? c? b?n d?ng virus n¨¤y c?ng nh? Virus tr¨ºn Boostector nh?ng n?i l?y nhi?m l¨¤ master boot record
  • 15. n Macro virus : ??y l¨¤ lo?i virus l?y tr¨ºn c¨¢c t?p d? li?u. C¨¢c ?o?n m? code c?a Virus tr¨ºn c¨¢c m? Visual Basic trong c¨¢c t?p Exel, MS word, MS Access, MS Poiwer point¡­ c¨® th? g?y l?y nhi?m Virus t?i c¨¢c t?p d? li?u ho?c t?p ch??ng tr¨¬nh kh¨¢c. Do vi?c x?y d?ng m?t ?o?n ch??ng tr¨¬nh macro
  • 16. n Virus hoax : L¨¤ c¨¢c th? ?i?n t? (E-mail) c¨® ch?a c¨¢c ?o?n ch??ng tr¨¬nh khi m? c¨¢c th? n¨¤y c¨¢c virus s? l?y v¨¤o m¨¢y t¨ªnh c?a ng??i s? d?ng v¨¤ s? th?c hi?n c¨¢c ch?c n?ng kh?ng ki?m so¨¢t ???c nh? l?y tr?m ??a ch?, g?i c¨¢c th? c¨® c¨¢c files th?ng tin tr¨ºn m¨¢y t¨ªnh c?a ng??i s? d?ng th?m ch¨ª xo¨¢ c¨¢c c¨¢c th?ng tin tr¨ºn ? ??a c?a m¨¢y t¨ªnh¡­,
  • 17. n Virus ¡°Con ng?a th¨¤nh T?-roa¡± : ??y l¨¤ lo?i virus kh¨¢ nguy hi?m l¨¤m thay ??i s? li?u, l?y c?p c¨¢c th?ng tin tr¨ºn m¨¢y t¨ªnh¡­ n¨® th??ng c¨® d?ng m?t file ???c g?i k¨¨m theo e-mail. n Virus h?n h?p : lo?i virus c¨® t?t c? c¨¢c t¨ªnh n?ng l?y nhi?m v¨¤ ph¨¢ ho?i tr¨ºn c? c¨¢c t?p, hay boot record. ??y l¨¤ lo?i virus tr¨ºn c¨¢c kh¨® di?t do ho?t ??ng ??ng th?i tr¨ºn nhi?u lo?i m?i tr??ng.
  • 18. n C¨¢c k? thu?t s? d?ng trong virus : n Th??ng tr¨² n ?n th?n (Stealth) n Bi?n h¨¬nh (Polymorphic)
  • 19. n C¨¢c ???ng th?m nh?p virus v¨¤o h? th?ng m¨¢y t¨ªnh : n Qua ng??i s? d?ng m¨¢y t¨ªnh n Qua h? th?ng th? ?i?n t? (E-mail) n Qua c¨¢c d?ch v? Internet
  • 20. ANTI-VIRUS n H? th?ng ph¨°ng ch?ng Virus s? ti?n h¨¤nh theo m? h¨¬nh hai l?p: Ch?ng Virus v¨¤ ph¨°ng Virus n Ph¨°ng virus : ng?n ch?n s? th?m nh?p c?a Virus qua c¨¢c ???ng l?y nhi?m ?? n¨ºu ? tr¨ºn nh? qua li¨ºn k?t Internet, mail¡­.. n Ch?ng virus : C?p nh?t v¨¤ c¨¤i ??t c¨¢c ph?n m?m ch?ng Virus m?i nh?t
  • 21. n C¨¢c quy tr¨¬nh b?o v? m¨¢y t¨ªnh : n ??ng k? : M¨¢y t¨ªnh ???c ??ng k? s? ???c nh¨®m ch?ng Virus m¨¢y t¨ªnh ??a v¨¤o danh s¨¢ch qu?n l? n C¨¤i ??t ph?n m?m ch?ng virus n Ph¨°ng ch?ng Virus m¨¢y t¨ªnh ??nh k? n Di?t Virus m¨¢y t¨ªnh trong c¨¢c tru¨°ng h?p b?t th??ng
  • 22. n Ch?ng Virus m¨¢y t¨ªnh th?m nh?p qua c?ng Internet : cho m¨¢y ch? di?t Virus m¨¢y t¨ªnh t?i c?ng Internet . n Ch?ng Virus m¨¢y t¨ªnh th?m nh?p qua th? ?i?n t? : cho m¨¢y ch? di?t Virus m¨¢y t¨ªnh t?i c¨¢c mail server