computer viruses

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1、ComputerVirusesVirusesarepotentiallydestructivesoftwarethatspreadsfromprogramtoprogramorfromdisktodisk.Computerviruses,likebiologicalviruses,needahosttoinfect;inthecaseofcomputervirusesthishostisaninnocentprogram.IfsuchaprogramistransferredtoyourPC,otherprogramsonyourPCwillbecomeinfected.Eventhough

2、somevirusesdonotintentionallydamageyourdata,allvirusestobemalicioussoftwaresincetheymodifyyourprogramswithoutyourpermissionwithoccasionaldisastrousresults.Ifyouhaveavirus,youarenolongerincontrolofyourPC.EverytimeyoubootyourPCorexecuteaprogramthevirusmayalsobeexecutingandspreadingitsinfection.Whilem

3、ostviruseshaven'tbeenwrittentobedestructive,almostallvirusescancausedamagetoyourfiles-mostlybecausethevirusesthemselvesareverypoorlywrittenprograms.Ifvirusesdestroynothingelse,theydestroyyourtrustinyourPC-somethingthatisquitevaluable.AreVirusesMostlyHype?Unfortunatelynot!Thereissomeconfusionaboutth

4、isissuebecausesomeextremeclaimshavebeenmaderegardingnumbersofvirusesandhowlikelyyouaretobecomeinfected.DuringtheMichelangelomediaextravaganzainearly1991,someexaggeratedfigureswerepresentedinthemediawhichledsomepeopletosuspectthatallviruseswerenothingbuthype.OnecompanywasquotedinInformationWeekthatb

5、asedontheirreports;oneoutoffourPCswasinfectedeverymonth!YoumayalsohearreportsoftherebeingfromtentothirtythousanddifferentPCviruseswiththenumberexpectedtodoubleinsixtoninemonths.So,arewefacedwithimpendingdoom?No,notquite.Thetruthisvirusesareverywidespreadbutarelativelysmallnumber(aboutone-hundred)ac

6、countforninetypercentofallinfections.Mostofthetwentythousandvirusesinourcollectionaresopoorlywrittenthattheywillnotspreadintherealworld.Manyofthesevirusesarecreatedbykidsthatcan'tevenprogram.Theyuseautomatedvirusescreationprogramsthatproduceverypoorqualityviruses.Thesevirusesaresoobviousthattheyrar

7、elyspreadinthewild.Still,virusesarearealthreatthatwecan'taffordtoignore.Viruseshavebeenfoundonbrand-newPCs,directfromthemanufacturer,andonshrink-wrappedsoftware,directfromthepublisher.Virusesarenotmerelyhyp