Tcs special program virus and how to avoid them
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PowerPoint slide show on Viruses - PowerPoint PPT Presentation

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TCS Special Program Virus, and How to Avoid Them. Fine Print. My views, not necessarily those of the Tulsa Computer Society Apologies to Symantec / Norton Anti-virus Concepts here are basic, given time constraints (but it is simple until you get infected)

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Tcs special program virus and how to avoid them
TCS Special ProgramVirus, and How to Avoid Them

Fine print
Fine Print

  • My views, not necessarily those of the Tulsa Computer Society

  • Apologies to Symantec / Norton Anti-virus

  • Concepts here are basic, given time constraints (but it is simple until you get infected)

  • There are always exceptions and nuances to the issues discussed

What are the basics
What are the Basics?

  • Practice Safe Computing

  • Install an Anti-Virus (AV) program and keep it up-to-date

  • Inform yourself with the facts, taken with a grain of salt

What is a computer virus
What Is a Computer Virus?

  • A computer virus is a program that infects an executable file (such as a program, start-up record, or macro) and replicates, infecting neighboring files without the knowledge of the PC user

  • Most viruses are relatively harmless

  • Some may cause random damage to data files and program files

  • Some are intended to destroy files

  • All viruses use resources by using disk space, memory, CPU processing time, and the time and expense in detecting and removing them

What is a trojan horse
What Is a Trojan Horse?

  • A Trojan horse, like a virus, may damage computer files

  • It is usually a single program, that like the old Greek trick, does something that the user does not expect

  • A Trojan horse does not replicate like a virus does

What is a dropper
What Is a Dropper?

  • A dropper is a program which installs a virus or Trojan Horse, often covertly

What is a worm
What Is a Worm?

  • A worm is a rogue program which spreads (usually) over network connections

  • It is not to be confused with a WORM CD drive, an acronym for Write Once, Read Many (times)

  • Worms are uncommon and are most often programming errors

What do viruses do
What Do Viruses Do?

Like a biological virus, computer viruses infect:

  • Other executable program files

  • Data files containing macros, especially Word and Excel macros

  • Operating system program files

  • Special disk program files called boot records and master boot records that your computer uses to start up

What do viruses do1
What Do Viruses Do?

  • Infect an executable file that is attached to an e-mail message

  • Destroy files or simply replicate or display messages such as “this computer is stoned”

What do viruses not do
What Do Viruses Not Do?

  • Cause hardware damage (usually)

A computer can get a virus by running an infected executable file, usually from a floppy disk, E-mail attachment or downloaded from the Internet

A computer cannot get a virus by opening a pure data file or e mail text
A Computer Cannot get a virus by opening a pure data file or E-mail text

Risky business

Risky Business

(Behavior that may infect your computer)

High risk profile
High Risk Profile

  • Network connection without professional administrator

  • Internet connection

  • No anti-virus software running

  • High modem use

  • Many downloaded programs from local BBSs or unknown internet pages

High risk profile1
High Risk Profile

  • Distribute and receive files, especially on floppy disks

  • Use pirated software

  • Collect bargain software from unknown sources

High risk profile2
High Risk Profile

  • Trade computer games

  • Let other people use your computer or use computer lab equipment

  • Use recycled floppy disks of unknown origin or floppies someone else has formatted

Medium use profile
Medium Use Profile

  • Network connection

  • Some downloaded programs from local bulletin boards or unknown internet pages

  • Use recycled floppy disks of unknown origin or floppies someone else has formatted

  • Use shared network programs

Medium use profile1
Medium Use Profile

  • Share files on floppy disks

  • Buy bargain or “swap meet” software

Low risk profile
Low Risk Profile

  • No network connection

  • Modem use for e-mail with few or no downloaded programs or downloads from commercial web pages and bulletin boards

  • Use just a few applications regularly

Very low risk profile
Very Low Risk Profile

  • Single-user PC

  • No network connection

  • No modem

  • Only use shrink-wrapped software from reputable dealers

  • Scan all floppy disks before first use

  • Doesn’t receive files on floppy disks

  • There is no way to guarantee that you will avoid infection. However, the potential damage can be minimized by taking the following precautions:

Make a clean boot disk
Make a Clean Boot Disk

  • Make a boot disk

  • Add essential program files to it

  • Scan it with AV software

  • Write-protect it

  • If you suspect an infection, boot from it then run AV software

Use anti virus software
Use Anti-Virus Software

  • Use reputable, up-to-date and properly-installed AV software

  • Update AV software virus definitions regularly

  • Scan floppies and HDD with AV software regularly

  • Scan programs before installation

Anti virus software programs




Dr. Web

F ‑Prot

McAfee and Dr. Solomon's (both owned by Network Associates)

Norton (Symantec)

Sophos sweep


Virus ALERT!




Anti-Virus Software Programs

Do some reading
Do Some Reading

  • If you're a home user, you may well get an infection sooner or later. If you're a business user, it will be sooner. Either way you'll benefit from a little background reading.

What to read
What to Read

  • Computer Magazines

    • PC World, Ziff Davis, WinMag, etc.

  • AV Documentation

    • If you use a shareware/freeware AV package, print a hard copy of the documentation before you get an infection

  • AV Software help files

What to read1
What to Read

  • Other types of resources

    • web pages like

      • CNet



    • newsgroups (alt.comp.virus)

    • Frequently Asked Questions (FAQ's)

    • Key word search on “computer virus”

Other safety measures
Other Safety Measures

  • Make sure both your home and work systems are protected

  • Get to know your AV software

  • If you're a business user, you need an enforceable virus policy

  • Practice Safe Computing


Business costs
Business Costs

  • Training a response team

  • Taking the team from their real jobs or hiring consultants when infection occurs

  • Cost of AV software

  • Cost of maintaining upgrades, subscriptions and tracking technological changes

Business costs1
Business Costs

  • Educating employees in the virus issues and safe computing

  • Cost in time of routine anti-virus measures, such as scanning hard disk drives

  • Cost of servicing false alarms

Business costs2
Business Costs

  • Resource utilization by undetected viruses

  • Formulating and enforcing a backup policy

  • Formulating and enforcing anti-virus policy

Personal costs
Personal Costs

  • Cost of AV software

  • Cost of maintaining upgrades every six months

  • Subscriptions for virus definitions

  • Cost in time of routine anti-virus measures, such as scanning hard disk drives

Personal costs1
Personal Costs

  • Computer speed - something else for the computer to do

  • Software bugs

  • Bloomington

    • 1992 from a clone vendor the office employed

  • Monkey

    • 1996 from working on a laptop while trying to find out why a PCMCIA card did not work. The virus was not the reason for the hardware problem

  • Larue

    • 1998, Excel macro virus from an infected file sent over the office network

  • Anti CMOS A

    • 1998, found while scanning for the Larue

  • Pretty Park

    • March, 2000, e-mail attachment

  • Numerous hoaxes


  • By news media to sell news and entertain us

  • By virus software vendors to sell software or enhance the company net worth


  • Please Help!

  • Did you hear? Tell everybody you know!

  • Chain Letters

Hoax virus
Hoax (Virus)

  • This virus will explode your hard disk drive

  • That virus will set your monitor on fire

  • The other virus will infect your cat


  • DOS file attributes (read only, hidden, system) protect executable files from infection

  • FDISK-ing your HDD will kill all viruses (it will certainly kill all your data)


  • Write protecting suspect floppies stops infection

  • I will be completely protected if I only...

  • It (software or hardware) was shrink wrapped so I can’t get a virus

  • This computer doesn’t work right, it must be a virus!!!!!

  • Update Virus Definitions

  • Demo of an Anti Virus Program

    • Scan a drive

    • Scan a file

    • Scan an e-mail attachment

  • Viruses in the News (from web pages)

  • Debunking hype, hoax and myth