Computer Crime & Security about computer

Computer Crime & Security

1. Usman Ahmad

2. Atypeofcrimeinwhichacomputeristhetarget or
toolforanillegalactivityiscalledcomputer crime.
Itofteninvolvesstealing,usingorselling
company'spersonaldata.
Atypeofcrimethatreferstoanillegalact
involvingtheInternetiscalledcybercrime.

3. Thepersonswhocommitcomputercrimesare
knownascomputercriminalsorcybercriminals.
DifferentTypesofcomputercriminalsareas
follows:
Hackers,Crackers,ScriptKiddie,CorporateSpy,
UnethicalEmployee,CyberExtortionist,Cyber
Terrorist.

4. Hacker
Apersonwhoaccessesacomputerornetworkillegally for
knowledgepurposesisknownashacker.
Thistermwasoriginallyusedforcomputer
enthusiasts.
Cracker
Apersonwhoaccessesacomputerornetworkillegally for
somenegativepurposeisknownasCracker.
Acrackermaydestroydataandstealimportant
informationetc.

5. Hacker Cracker
Thegoodpeoplewhohackforknowledgepurposes. Theevilpersonwhobreaksintoasystemforbenefits.
Theyareskilledandhaveaadvanceknowledgeofcomputers
OSandprogramminglanguages.
Theymayormaynotbeskilled,someofcrackersjustknowsa
fewtrickstostealdata.
Theyworkinanorganisationtohelpprotecting theredata and giving
themexpertiseoninternetsecurity.
Thesearethe personfromwhichhackersprotect organisations
.
Hackerssharethe knowledgeandnever damagesthedata.
Iftheyfoundanyloopholetheyjustdeletethedataor
damagesthe data.
Hackersaretheethicalprofessionals.
Crackersareunethicalandwanttobenifit themselvesfrom illegal
tasks.
Hackersprogramorhackstocheckthe integrityand
vulnerability strengthofanetwork.
Crackersdonotmakenewtoolsbutusesomeoneelsetoolsfor
therecauseandharmthenetwork.
Hackershavelegalcertificateswiththeme.gCEHcertificates.
Crackersmayormaynothavecertificates,astheremotiveisto stay
anonymous.

6. ScriptKiddie
Apersonwhoattemptstoaccessacomputerornetworkillegally
withouttechnicalknowledgeisknownasscriptkiddie.
Thescriptkiddiesoftenusehackingorcrackingsoftwareto
accesscomputers.
CorporateSpy
Apersonwhoishiredtobreakintoaspecificcomputerisknown as
corporatespy.
Corporatespieshaveexcellentcomputerandnetworkskills.
Someorganizationshirethemtoidentifysecurityrisksinthe
organizationetc.

7. UnethicalEmployee
Theunethicalemployeesmayaccessthecomputerfor
differentreasons.
Somemaygetfinancialgainsbysellingconfidential
information.
Someunhappyemployeemaydothistogetrevenge
etc.

8. CyberExtortionist
Apersonwhousesemailastoolforextortion
(Blackmailing)isknownascyberextortionist.
Suchpersonssendemailtoacompanywithathreat.
Theytellcompanytopaymoneyotherwisetheywill
exposeconfidentialinformationofcompanyetc.

9. CyberTerrorist
ApersonwhousescomputerInternetornetworkto
destroyordamagecomputerforpoliticalreasonis
knownascyberterrorist.
Forexample,cyberterroristsmaydestroyairtraffic
controlsystem,electricity-generatingsystemsor
telecommunicationsystemofacountryetc.

10. LogicBomb
Itisaprogramthattriggersundercertainconditions.
Itisusuallyactivatedatacertaindate.
Itmaybeplantedincommercialsoftwarelikeshareware
software.
DataDiddling
Itisaprocessofchangingdatabeforeorasitentersthe
system.
Theauditorsmustverifytheaccuracyofthesourcedata and
theprocessingthatoccurs.
MethodsUsedby ComputerCriminals

11. Denialofservice
Itslowsdownacomputersystemornetwork.
Itfloodsacomputerornetworkwithrequestsfor
informationordata.
Theserverunderattackreceivessomanyrequeststhatit
cannotrespondtolegitimateusers.
Piggybacking
Itisaprocessofenteringthesystembyridingontheback of
anauthorizeduser.
Itoccurswhenanauthorizeduserdoesnotlogoffthe
systemproperly.Anillegalusermaycontinuewhere
originaluserleft.
MethodsUsedby Computer
Criminals

12. SalamiTechnique
Itisaprocessofgettingasmallamountofmoneyillegallyfromalarge
financialsystem.
Scavenging
Itisaprocessofsearchingcompany'strashcanstofinduseful
information.
Thethievessearchgarbageandrecyclingbinsofindividualstofind bank
accountnumbersetc.
TrapDoor
Itisanillegitimateprogramthatitselfwithinacompletedlegitimate
program.
Itallowssubsequentsentrybyunauthorizedusertochangethe
program.
MethodsUsedby Computer
Criminals

13. TrojanHorse
Itisaprogramthathidesitselfwithinausefulprogram.
Itexecutesillegaldestructiveinstructionsinthemiddleof a
programsuchascomputergame.
FormatCisanexampleofaTrojanHorse.
Zapping
Thezappingsoftware,isdesignedtobypassallsecurity
systems.
MethodsUsedby Computer
Criminals

14. Securityisasystemthatisusedtoprotecta
computersystemanddata.
Itprotectsfromintentionalandaccidental
damageoraccessbyunauthorizedpersons.
Acomputercandetectwhethertheuseris
authorizedornot.

15. Lossofhardware
Securityviolationmaycauselossofhardwareinthe
organization.
Forexample,anunauthorizedusermaystealinequipmentetc.
LossofProcessingAbility
Thesystemmayloseprocessingabilitywheninstallationofthe
systemisreturnedtoformerstateafteranysecurityviolation.
Anorganizationmayfaceseverelossifprocessingabilityis
suspended.
Forexample,abankcanlossthebusinessifthesystemstops
processing.

16. LossofSoftware
Asecurityviolationmaycauselossofsoftware.
Thesystemmaynotworkproperlyifthesoftware-filesare
damagedordeleted.
LossofData
Lossofdataisoneofthemostimportantproblems
causedbysecurityviolation.
AnorganizationcannotWorkproperlyifimportantdatais
lost.
Thelostdataisverydifficulttocollectagainforbig
organization

17. Theprotectionofdataiscalleddatasecurity.
Datastoredincomputercanbelostdueto
differentreasons.
Itcanbelostaccidentallyorsomeonecandamage it.
Datacanbelostcompletelyorpartially.
Dataismorevaluableandimportantthanthe
computeritself.

18. Itshouldbesavedinsuchawaythatitmaynotbelost or
damaged.
Someorganizationsobtaindatafromtheusersand
storedataonlinetoprovidefastServices
Someexamplesareasfollows:
Acreditcardcompanymaystoredataofitscustomers
online.
Abankmayprovideonlineservicesusingonlinedata
storagefortherecords.
Auniversitymayprovidethefacilityofonlineresults.

19. Datasecurityisveryimportanttorunsomeorganizations
successfully.
Apersonmayenterthenetworkofanorganizationand
gainunauthorizedaccesstothedata.
Forexample,hemayusethecreditcardnumberof
anotheruserforshopping.
Iftheunauthorizedpersondeletesimportantdata,the
businessoftheorganizationmaybedamagedseverely.
Soitisveryimportanttoprotectdatafromillegaland
unauthorizedaccess.

20. Computersecuritythreatcanbea
computerprogram,
anevent
oraperson
thatviolatescomputersecurity.

21. Itmayalsoaffecttheworkingifcomputer.
Differentsecuritytreatsareasfollows:
1.Hacker
2.HardwareTheft&Vandalism
3.SoftwareTheft
4.InformationTheft
5.SystemFailure
6.Virus
7.Phishing software
8.Malware software
9.Adware software
10.DenialofServiceAttack

22. Apersonwhoaccessesacomputer,networkanditsresources
illegallyisknownashacker.
Hackersarecomputerexpertsandusetheircomputer
knowledgefornegativepurpose.
Thehackermaystealthefollowing:
Theinformationoftheclientorcustomer
Creditcarddetailsforunauthorizeduse
Passwordstoaccesscomputersandnetworksillegally
Emailpasswordstouseemailaccountwithoutuser'sknowledge
1. Hacker

23. Hardwaretheftisaprocessofstealingthe hardware
equipmentsuchasharddiskormonitor etc.
Hardwarevandalismisaprocessofdefacingthe
hardwareequipment.
Forexample,anemployeeinanorganizationmay
damagekeyboardorcutthewiresetc.
2. Hardware theft & Vandalism

24. Softwaretheftmeansthatapersoncansteal
softwaremedia,erasesoftwareprogramorcopy it
withoutpermission.
Forexample,someonecanstealtheCD-ROMthat
containsthesoftwareprogram.
Anangryemployeemaydeletetheinstalled
softwarefromthecomputer.
3. Software Theft

25. 4.InformationTheft
Informationtheftisanothercriticalsecurity
threat.
Itisaprocessofstealingpersonalorconfidential
informationwithoutpermission.
Thestoleninformationcanbefurtherusedfor
illegalactivities.
Forexample,someonemaystealthecreditcard
numberofanotherpersonanduseittobuythings
online.

26. following:
5.SystemFailure
Systemfailureisalsoanimportantsecuritythreat.
Itoccurswhenthesystemdoesnotfunctionproperly for
longertime.
Systemfailuremaycausefurtherlossofdata,
softwareandhardwareetc.
Itoccursduetovariousreasonsincludingthe
✓Obsoletehardware
✓Naturaldisastersuchasflood,fireorstorm
✓Fluctuationinpowersupplyetc.

27. 6.Virus
Avirusisacomputerprogramthatmaydisturbthe
normalworkingofacomputersystem.
Virusattachesitselftofilesstoredonflashdrives,
emailattachmentsandharddisks.
Itmaycausemanydamagestoacomputersystem.
Aviruscan:
1.Damagedataorsoftwareoncomputer.
2.Deletesomeorallfilesonthecomputersystem.
3.Destroyalldatabyformattingharddrive.
4.Displayapoliticalorfalsemessageeveryfewtimes.

28. 7. Phishing software
•Phishing software isa type of cybersecurity software that
identifies and blocks phishing content in emails, websites, or
other data access methods.
•Phishing attacks are fraudulent emails or text messages that
contain links to malicious websites that may contain malware.
•Some examples are includes:
•IronScales:A self-learning email security platform that uses
AI and human interaction to prevent phishing attempts
•Barracuda Sentinel:An AI-based protection that learns a
business's communication patterns to detect personalized
fraud in real-time
•Wifiphisher:A security tool that simulates and tests wireless

29. 8. Malware Software
•Malware, or malicious software, isany software that is
intentionally designed to disrupt a computer, server, or
network.
•It can also leak private information, gain unauthorized access,
or interfere with the user's privacy.
•Malware can take many forms, including viruses, worms,
Trojan horses, ransomware, and spyware.
•Adware isa type of malware that displays ads on a
computer or mobile device, or redirects search results to
advertising websites.
•It can also collect user data for marketing purposes.
•Adware is designed to generate revenue by serving ads to

30. 9. Adware Software
•Adware isa type of malware that displays ads on a computer
or mobile device, or redirects search results to advertising
websites.
•It can also collect user data for marketing purposes.
•Adware is designed to generate revenue by serving ads to an
internet user.

31. Adenialofservice(DOS)attackslowsdowna
computersystemornetwork.
Itfloodsacomputerornetworkwithrequestsfor
informationordata.
Themostcommontargetsofthisattackare
internetserviceproviders(ISPs)andcertain
websites.
Theserverundertheattackreceivessomany
requeststhatitcannotrespondtolegitimate.
10. Denial of service attack

32. Anadditionalcopyofdataorinformationstoredon
secondarystoragemediaiscalledthebackupofdata.
Thecommonmediaofbackuparezipdisk,magnetic
tape,floppydisk,CD-ROMandharddisketc.
Thecomputersystemcanbedamagedduetomany
reasons.
Thedatastoredonthesystemmayalsobelost,
deletedoraltered.

33. Sometimesthedataisveryimportantitcannotbe
createdagain.
Forexample,computerinabankmaycontainthe
recordsofallmoneytransactions.
Thebackupofdataisusedifyoursystemcrashes
accidentallyandthedatastoredinitislost.

34. 1.Animportantfilecanbedeletedaccidentally.
2.Theusermayoverwriteapartorwholeofanexisting
file.
3.Amechanicalfailureinthecomputermayresultinloss of
data.
4.Avirusmaydamagethedatastoredonthecomputer.
5.Thecomputersystemmaybestolenbyanybody.
6.Thecomputersystemmaybedamagedduetofireor
powerfailure.

35. Itisveryimportanttotakethebackupofdata
regularly.
Itshouldbestoredatasafeandprotectedplace.
Inabidorganization,thebackupisnormally
storedonacentralizednetworkedcomputer.
Inasmallorganization,thebackupisstoredon
floppydisks,Zipdisks,orCD-ROM.

36. Therearetwowaystotakethebackupofdata:
1.CompleteBackup
2.IncrementalBackup

37. Backupofdataontheharddiskiscalledcomplete
backup.
Theadvantageofthisbackupisthattheentirehard
diskisbacked-up.
Thedatacanberestoredfromthisbackupincaseofa
probleminthesystem.
Ittakesmoretimeandstoragecapacitybecausethe
entiredataofharddiskiscopied.
1. Complete Backup

38. Incrementalbackupcreatesacopyofonlythedata
thatisnewlycreatedormodifiedsincethelast
backup.
Thisprocessisperformedautomaticallyinsome
software.
Inthistypeofbackup,theentirediskisnotcopied.
Ittakeslesstimeandspacetancompletebackup.
2. Incremental Backup

39. Differenttypesofmediacanbeusedforbackup of
data.
Theselectionofmediadependsuponthenature
andquantityofthedatatobebackedup.
1.USBFlashDrive
2.ExternalHardDisk
3.MagneticTape

40. USBFlashDrive
USBflashdriveisusedfordatabackup.
Itisveryeasytouseitbecauseitislightandsmallinsize.
Itisavailableindifferentshapes,sizesandCapacities.
ThestoragecapacityofUSBdriveis512MBto100GB
ExternalHardDisk
ItisaseparateharddiskandisconnectedtoUSBorFireWireportonthesystemunit.
Itsstoragecapacityisupto4TBandmore.
Itcanbeusedtobackupimportantfilesorentireinternalharddisk.
MagneticTape
Itisaconventionalandreliablemediaforbackup.
Itisusedforbackingupseveralthousandmillionbytesofdata.
Itismoreexpensivemedia.
Thedatastoredonthismediacannotbeaccessedrandomly.

41. Acomputervirusisaprogramthatmaydisturbthe
normalworkingofacomputersystem.
Virusattachesitselftofilesstoredonflashdrives,
emailattachmentsandharddisks.
Afilecontainingavirusiscalledinfectedfile.
Inthisfileiscopiedtoacomputer,virusisalsocopied to
thecomputer.
ExamplesofcomputervirusareCascade,Zmist,
BlasterandAntiExe.

42. Whenthecomputervirusstartsworking,itis
calledtheactivationofvirus.
Avirusnormallyrunsallthetimeinthecomputer.
Differentvirusesareactivatedindifferentways.
Manyvirusesareactivatedonacertaindate.
For,example,popularvirusFridaythe13thvirusis
activatedonlyifthedateis13anddayisFriday.

43. Computerviruscannotdamagecomputerhardware.It
maycausemanydamagestoacomputersystem.
Aviruscan:
1.Acomputerviruscandamagedataorsoftwareonthe
computer.
2.Itcandeletesomeoralltilesonthecomputer.system.
3.Itcandestroyalldatabyformattingharddrive.
4.Itmaydisplayapoliticalorfalsemessageeveryfew
times.

44. Avirusisspreadondifferentcomputersdueto
thefollowingreasons:
1.InfectedFlashDrivesordisks
2.EmailAttachments
3.InsecureWebsites
4.NetworksVirus
5.PiratedSoftware

45. Flashdrivesanddisksarethemaincauseof
spreadingviruses.
Flashdrivesanddisksareusedtotransferdata
fromonecomputertoother.
Aviruscanalsohecopiedfromonecomputerto
otherwhentheusercopiesinfectedfilesusing flash
drivesanddisks.
1.InfectedFlashDrivesordisks

46. Mostofthevirusesspreadthroughemails.
Emailattachmentisafilethatissentalongwithanemail.
Anemailmaycontainaninfectedfileattachment.
Viruscanspreadiftheuseropensanddownloadsanemail
attachment.
Itmayharmthecomputerwhenitisactivated.
Itmaydestroyfilesontheharddiskormaysendthevirus
automaticallytoallemailaddressessavedintheaddressbook.
2. Email Attachments

47. 3. Insecure Websites
Thousandsofinsecurewebsitescaninfectcomputer withviruses.
Thesewebsitesaredevelopedtospreadvirusesorotherunethical
material.
Thevirusistransferredtotheuser'scomputerwhen thismaterial
isdownloaded.
Thesewebsitesmayaccess.thecomputer automatically
whentheusersvisitthem.

48. 4. Networks Virus
Itcanspreadiftheuserconnectstoacomputer
networkthatcontainsvirus.
Theinternetisanexampleofsuchnetwork.
Whenauserdownloadsafileinfectedwithvirus
fromInternet,thevirusiscopiedtocomputer.
Itmayinfectthefilesstoredonthecomputer.

49. Anillegalcopyofsoftwareiscalledpiratedsoftware.
Viruscanspread,ifuserinstallspiratedsoftwarethat
containsavirus.
AvarietyofpiratedsoftwareisavailableinCDsand
fromtheinternet.
Somecompaniesintentionallyaidvirusinthe
software.
Thevirusisautomaticallyactivatediftheuserusesthe
softwarewithoutpurchasinglicense.
5. Pirated Software

50. VirusinfectscomputersystemifAntivirussoftwareisnotinstalled.
LatestAntivirussoftwareshouldbeinstalledoncomputertoprotectitfromviruses.
Acomputersystemcanbeprotectedfromvirusesbyfollowingtheseprecautions:
1.
2.
3.
4.
5.
6.
Thelastanti-virusshouldbeinstalledonthecomputer. The
antivirussoftwaremustbeupgradedregularly.ry. Thefloppy
diskshouldbescannedforvirusesbeforeuse. Junkor
unknownemailsshouldnotbeopened.
Unauthorizedorpiratedsoftwareshouldnotbeinstalledonthecomputer. An
Importantwayofprotectionagainstvirusistheuseofbackupofdata.The
backupisusedifthevirusdeletesdataormodifiesit.
FreewareandsharewaresoftwarefromtheInternetnormallycontainviruses.Itis
importanttocheckthesoftwarebeforeusingthem.
7.

51. Awormisaprogramthatcopiesitselfrepeatedly in
memoryorondiskuntilthereleftnospace.
Thecomputermaystopworkinginthissituation.
Wormsspreadsfromonecomputertoanother
throughnetworks.
SomeexamplesofwormareSQLSimmer,'the
BlasterWorm,sasser,ILOVEYOUandMelissa.

52. ATrojanhorseorTrojanisatypeofmalwarethat is
oftenhiddenaslegitimatesoftware.
Trojanscanbeemployedbycyber-thievesand
hackerstryingtogainaccesstousers'systems.
malwaretypicallyconsistsofcodedevelopedby cyber-
attackers,designedtocauseextensivedamage todataand
systemsortogainunauthorizedaccess toanetwork.

53. Computer
Worm
•Canself-
replicate
•Theydonot
needto
attach
themselves
withexisting
programs
Computer
Virus
•Canself-
replicate
•Attach
themselves
withexisting
programs
Trojan
Horse
•Cannotself-
replicate
•Usesocial
engineering
techniques
tospread.

54. CodeRed(Worm)
ItisawormthatinfectsacomputerrunningMicrosoftIISServer.
ItlaunchedtoDoSattackonthewebsiteofWhiteHouse.
Itallowsthehackertoaccesstheinfectedcomputerremotely.
Nimda(Worm)
Itisawormthatspreadsitselfusingdifferentmethods.
Itdamagescomputerindifferentways.
Itmodifiesfiles,alterssecuritysettingsanddegrades
performance.

55. Sircam(Worm)
Itisdistributedasanemailattachment.
Itmaydeletefiles,degradeperformanceandsendthe files
toanyone.
Melissa(Virus)
Itisavirusthatisdistributedasanemailattachment.
ItdisablesdifferentsafeguardsinMSWord.
Itsendsitselfto50peopleifMicrosoftOutlookis
installed.

56. Ripper(Virus)
Itcorruptsdatafromtheharddisks.
Concepts(Virus)
ItistransferredfromoneMSWordfiletootherifboth files
inmemory.
Itisalsotransferredasanemailattachment.
Itsavesthefileintemplatedirectoryinsteadofits
originallocation.

57. One-Half(Virus)
Itencryptsharddisksoonlythevirusmayreadthedata.
ItdisplaysOne-Halfonthescreenwhentheencryptionin half
completed.
Michelangelo(Virus)
ItdestroysalldataonharddiskonMarch6.
Cascade(alsoknownasHerbstlaubinGermany)
(Virus)
Itpicksrandomtextcharactersanddropsthemtothe
bottomofthescreen.