5.2 VIRUS TIN HOC

CC KHI NIM C BNThuat ng Virus tin hoc dung e ch cac chng trnh may tnh do con ngi tao ra. Cac chng trnh nay thng ngan, tinh vi va co kha nang bam vao cac file khac nh mot vat the ky sinh. Chung co kha nang t nhan ban, t sao chep chnh no len nhng file khac e lay lan ma ngi s dung khong hay biet.

oi tng tan cong cua chung la cac a cng va a mem cha d lieu, lam cho cac file kieu .COM, .EXE chay sai hoac khong chay; huy hoai cac file khac tren a. Do cach thc hoat ong cua chung giong virus sinh hoc nen ngi ta at cho chung cai ten "Virus"

Da vao cac phng tien giao tiep may tnh nh a, mang, nhat la Internet chung lan truyen va co mat khap ni tren the gii vi so lng ong khong ke xiet. Co the noi rang ni nao co may tnh, ni o co virus tin hoc, tam hoat ong cua virus tin hoc la pho bien vo cung. Moi Virus co mot ten, nh Klez, Frethem, Yaha-E, Code Red, SirCam, Nimda, HaNoi, VN19,

L DO TO VIRUS Khi au la e vui ua, nghch ngm, e chng to tai nang tin hoc, e c ngi khac chu y hay e the hien mot y tng hao thang, noi loan, bat man. Ke en, tao ra Virus e ban chng trnh tr Virus. Dung Virus e pha hoai oi thu canh tranh, bao ve ban quyen phan mem, chong lai cac hanh ong sao chep trom Ngay nay, vi s phat trien mau le cua Internet, ch can 1 gi co the phat tan Virus tren toan the gii, Virus a tr thanh vu kh kinh te, xa hoi quan trong va a en mc tr thanh vu kh chnh tr.

C TNH CA VIRUST nhan len cc nhanhChiem dung tai nguyen cua nay, lam cham he thongT t lam hong a cngB mat mang cac file he thong va thong tin i mat khoi mayChng trnh Virus gon, nhe, chay nhanh, tinh vi va hieu qua

TC HI CA VIRUS Cai ma Virus tan cong trc tiep la d lieu tren may. Song tren Internet th Virus tan cong vao cac WebSite, lam te liet hoat ong, ac biet la cac hoat ong kinh te, thng mai ien t, thong tin lien lac, cac kho d lieu, Nhieu Virus khi lay vao may co kha nang t ong gi i cac file van ban trong may va nh vay se lam lo nhng thong tin noi bo hay ca nhan quan trong.

TC HI CA VIRUS Nam 2001, Virus Love Bug lam the gii thiet hai khoang 9 ty USD. Virus Code Red tan cong ngon i chng 2 ty USD, cha khac phuc xong th Virus Nimda lai gay mot cn bao mi va c lien tuc nh the.Tac hai cua Virus ngay mot ln, ngay mot tram trong, nhat la trong thi ai Thong tin. The gii a co nhieu cach thc e oi pho, song co the d oan rang ch co the han che tac hai cua no ch khong the tieu diet no.

DU HIU B VIRUSNgoai viec pha hoai thc s, cac virus con an nau trong may ch thi c, khong phai luc nao cung de dang phat hien may tnh ang b nhiem virusTrieu chng ro ret nhat la may tnh lam viec bat bnh thng, cham lai; a cng b mat d lieu hoac khong khi ong c hoac nhan ra a cng

DU HIU B VIRUSCo khi gap nhng hien tng la nh ban phm khong tuan theo s ieu khien hoac thnh thoang lai tuon ra nhng dong ch v van, nhng om mau nhay nhot tren man hnh hoac khi loa cua may lai nhai nhng ieu nhac v vanTram trong hn, toan bo d lieu qu gia tren a bien mat hoac ch la mot m rac ri.

Kch thc cua cac tap tin nhiem F-Virus bao gi cung ln hn kch thc ban au. ay chnh la dau hieu ac trng c ban e nhan dang s ton tai cua F-Virus tren file thi hanh

CCH LY LANTrc ay, Virus lay lan chu yeu qua sao chep cac a mem t may nay sang may khac. Ngay nay, ngoai a mem, Virus con lay lan rat nhanh thong qua cac dch vu Internet nh th ien t E-Mai, World Wide Web, DownLoad File,

CCH LY LANCach thc lay lan ngay cang tinh vi, phc tap. Virus hoat ong co tnh t ong rat cao. Nhieu Virus t cai at chng trnh len may va sau o t gi chnh no ti tat ca cac a ch e-mail ma no tm thay tren may nay.Nhieu Virus con t ong tm va gi i nhng file van ban co tren may ma no lay nhiem.Nhieu Virus con t ong tm va gi i password

PHN LOI VIRUS Da vao oi tng lay lan, tam chia virus thanh 3 nhom chnh:B-virus (Boot virus)F-virus (File virus)Macro-virus

B-virus (Boot virus)B-Virus tan cong vao Master Boot, Boot Sector cua a, bang FAT (File Allocation Table), bang Th muc (Root directory)B-Virus ch co the c kch hoat khi khi ong may tnh bang a nhiem. Luc nay he thong cha c mot he ieu hanh nao kiem soat. Nh ac iem nay ma no co kha nang lay tren moi he ieu hanh.

F-virus (File virus) F-virus gan len vao file .COM va .EXE mot oan ma va khi file nay thc hien, oan ma se c kch hoat, thng tru trong vung nh, khong che viec truy xuat file, tm cac file thi hanh sach khac e t gan chung vao.F-virus de dang c kch hoat do tan xuat chay cac file .COM, .EXE cua he thong rat cao. Nhc iem cua F-virus la ch lay tren mot he ieu hanh xac nh.

F-virus co the lay vao vung nh, tao xung ot ve tnh nhat quan cua vung nh, khai thac vung nh mot cach khong thch hp, lam roi loan cac trnh ieu khien thiet b hien hanh... F-virus co the pha hoai d lieu bang cach dung nhng chc nang ve file e thay oi noi dung cac tap tin van ban, chng trnh nguon, bang tnh, tap tin c s d lieu, tap tin nh phan...

Macro Virus Virus chon ngon ng macro cua Microsoft Word lam phng tien lay lan tren moi trng Winword. T van ban nhiem, Macro Virus se c a vao NORMAL.DOT, roi t ay chung t chen vao cac van ban sach khac Dang th hai cua Macro Virus la lay vao bang tnh cua Microsoft ExcelMacro Virus ch pha hoai d lieu cua may tnh mot cach ngau nhien tai nhng a ch khong xac nh

9 HNG DN V PHNG VIRUSHAN CHE DUNG CHUNG MAYDUNG PHAN MEM CO BAN QUYENKIEM TRA A LA TRC KHI S DUNGTHNG XUYEN DUNG CAC CHNG TRNH PHAT HIEN-PHONG-DIET VIRUS MI NHAT

5-THN TRNG KHI NHN E-MAIL HOAC DOWNLOAD FILE 6-THNG XUYEN SAO LU CAC D LIEU QUAN TRONG RA CAC THIET B LU TR

7-E PHONG B-virusNG KHI ONG MAY T A MEM. NEU BUOC PHAI KHI ONG, HAY CHAC RANG A MEM NAY SACH8-E PHONG F-VIRUSKHONG C CHAY CAC CHNG TRNH KHONG RO NGUON GOC. NEU NGHI NG, S DUNG MOT PHAN MEM CHONG VIRUS NAO O E KIEM TRA A TRC KHI S DUNG.

9-E PHONG MACRO VIRUSKHI NHAN MOT FILE .DOC HAY .XL? HAY NH KIEM TRA VIRUS TRC KHI M KHI M TAP TIN, CHON MENU TOOL/MACRO CUA WINWORD E TM MACRO LA. NEU CO, XOA NGAY. SAU O THOAT KHOI WINWORD, XOA LUON TAP TIN NORMAL.DOT.

Dung chung mayNhan file kem E-Mail l

KHNG M FILE L NH KM E-MAILKHNG XEM MAIL L NGAY C TRONG CH PREVIEW

SAO LU L BIN PHP QUAN TRNG NHT

SAO LU THNG XUYEN HOAC NH KY D LIU RA :-A MEM-A CNG TH 2-FLASH ROM-A CD-BANG T

CHN THIT B SAO LUSao lu nh : di 2 GB- a quang t usb 1gb- a iomega zip usb 250 mg- cd-rw *Sao lu trung bnh : 2 GB n 20 GB- cng cm tay 20 gb- dvd-rw *Sao lu y : trn 20 GB - gn ngoi 80 gb c tch hp phn mm sao lu h thng *- bng t dung lng rt cao, rt tt

8 LU V SAO LULp danh sch cc tp tin cn sao luQuyt nh mc sao lu thng xuynDuyt li d liu sau sao luTo nhiu bn v ct nhiu niBo v, bo qun tt bn saoKhng dng mt cng ngh duy nhtDng chng trnh sao lu vi nhiu tnh nng ch ng ch ko thHy chy th phn sao lu

NH NGY THNG GIVIRUS CIH CHERNOBYL 26-4START/SETTINGS/CONTROL PANEL

A MM CU HL a mm sch c cha cc file sch cn thit d phng S dng khi Windows h hay ci t li H iu hnh, format a cng, khi my b VirusNu mua my ci Windows th phi km theo a khi nga cha MS-DOS, vi COMMAND.COM v vi file khc

TO A MM CU Ha a sach vao o A cua mot may sachStart/Settings/Control Panel/Add/Remove Programs/Startup disk/Create diskOK Copy phan mem diet virus vao a A (hoac vao mot a sach khac)Nh cai chot chong ghi cho a khi ong va a cha Anti-Virus.

CC ANTIVIRUS

Chng trnh diet virus la chng trnh c thiet ke e do tm cac oan ma virus a c gan vao cac chng trnh khac va loai tr cac oan ma ay, phuc hoi lai chng trnh nh trc khi b lay nhiem. Cac Anti-Virus ngoai thng pham nh SCAN cua McAfee, Norton Anti-virus cua Symantec, Toolkit Cac Anti-Virus noi free nh D2 va BKAV

Hn ch ca AntivirusCac phan mem Anti-Virus ong vai tro tch cc nhat trong viec chong Virus song :Ch co tac dung tren cac loai virus a biet Ch la mot chng trnh kiem tra va phuc hoi cac tap tin chng trnh a b lay nhiem virus Khong nen at niem tin vao mot chng trnh Anti-Virus nao o Khong co tac dung vi cac virus mi xuat hien hang ngay

CC LU Phai chay Anti-Virus sach trong tnh trang bo nh sach Ra quet 1 lan; khi ong lai may va ra quet lan 2Nen s dung ca Anti-Virus ngoai nhap va noi aDung phoi hp ong thi cac AntivirusChay nh ky ch khong ch khi b nhiem Dung AntiVirus mi nhat

Neu may van khi ong c t a cng th dung chnh nhng phan mem diet virus a cai tren a cng e quet virus v cac phan mem nay a co c che t bao ve. Nhng khi co thong bao virus xuat hien trong bo nh, phai dung a mem cu ho.Neu khong khi ong c t a cng th phai dung a mem cu ho.

BKAV2002McAfeePHAN MEM DIET VIRUS

LY ANTIVIRUS TRN MNG

LY BKAV TRN WEBhttp://www.vnn.vn/vnn1/bkav

LY D2 TRN WEBhttp://www.vnn.vn/vn1/d2

CHY BKAV

CHY D32

BT VIRUS Neu nhiem virus mi, chep cac file b lay nhiem gi en cac a ch Anti-VirusVi new Macro Virus, chep file .DOC, .XL? Vi new B-Virus, oc a bang lenh DIR A: e bat no len aVi new F-Virus , chep cac file tang kch thc cua tap tin .COM, .EXE Nen ghi nh kch thc file thong dung nh DOSKEY.COM. Trong moi trng nhiem New F-Virus, chay DOSKEY.COM

D BOCac loai virus se lay nhiem khong phai vao hang tram ngan may tnh ma la hang trieu may tnhCac virus cua tng lai co the hoat ong theo nhng xu hng nh sau: Khai thac cac lo hong phan mem cha c phat hien Lay lan theo nhng cach thc khac nhau nh virus lai tao, hoi thoai trc tuyen,Cac chng trnh con pha hoai an trong VirusTham nhap ien thoai di ong

NGHIEN CU E TAO LAP CAC ANTI-VIRUS CO KHA NANG NHAN DANG VIRUS MA KHONG CAN CAP NHAT THEO C CHE MIEN DCH. TAO CAC PHIEN BAN TH NGHIEM HNG TI HE CHNG TRNH CHONG VIRUS THONG MINH CO KHA NANG D BAO S XUAT HIEN CUA CAC LOAI VIRUS MIBIN PHP

TM V LP CC L HNG TRONG CC PHN MM NGN CHC HACKER THM NHP PHT TN VIRUS

XAC LAP VA THC THI CAC IEU KHOAN TRONG BO LUAT HNH S VE TOI DANH PHA HOAI D LIEU

Xem thm bi vit v Bo v d liu 8-2002