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- COMPUTER VIRUSES
-
- Cateye
-
- <1>WHAT IS A COMPUTER VIRUS:
-
- The term usually used to define a computer virus is:
- ' A computer virus is often malicious software which
- replicates itself'
- [ Podell 1987 for similar definition ]
-
- - COMPUTER VIRUSES ARE BASICALLY PROGRAMS, LIKE A
- SPREADSHEET OR A WORD PROCESSOR.
- - PROGRAMS WHICH CAN INSERT EXECUTABLE COPIES OF ITSELF INTO
- OTHER PROGRAMS.
- - PROGRAMS THAT MANIPULATES PROGRAMS, MODIFIES OTHER
- PROGRAMS AND REPRODUCE ITSELF IN THE PROCESS.
-
-
-
- Comparing Biological viruses & Computer viruses
-
- *************************************************************
- * Attack specific * Attack specific *
- * body cells * programs (*.COM *.EXE) *
- *************************************************************
- * Modify the genetic information * Manipulate the program: *
- * of a cell other than previous 1* It performs tasks *
- *************************************************************
- * New viruses grow in the * The infected program produces *
- * infected cell itself * virus programs *
- *************************************************************
- * Infected cells aren't infected * Program are infected only once*
- * more than once by the same cell* by most programs*
- *************************************************************
- * An infected organism may not * The infected program can work *
- * exhibit symptoms for a while * without error for a long time *
- *************************************************************
- * Not all cells with which the * Program can be made immune *
- * virus contact are infected * against certain viruses *
- *************************************************************
- * Viruses can mutate and thus * Virus program can modify *
- * cannot be clearly told apart * themselves & possibly escape *
- * * detection this way *
- *************************************************************
-
-
-
- However, " computer virus " is just another name for a class
- of programs. They can do anything that another program can.
- The only distinguishing characteristic is the program has
- ability to reproduce and infect other programs.
-
-
-
- <2>WHAT KIND OF PROGRAM ARE CHARACTERIZED AS A VIRUS PROGRAM:
-
- - PROGRAM WHICH HAS CAPABILITY TO EXECUTE THE MODIFICATION
- ON A NUMBER OF PROGRAMS.
- - CAPABILITY TO RECOGNIZE A MODIFICATION PERFORMED ON A
- PROGRAM.(THE ABILITY TO PREVENT FURTHER MODIFICATION OF
- THE SAME PROGRAM UPON SUCH RECONDITION.)
- - MODIFIED SOFTWARE ASSUME ATTRIBUTES 1 TO 4.
-
- <3>HOW DOES A VIRUS SPREAD:
- A computer virus can only be put into your system either by
- yourself or someone else. One way in which a virus can be
- put into your computer is via a Trojan Horse.
-
- -TROJAN HORSE IS USUALLY CONTAMINATED IN DISKS WHICH ARE
- PARTICULARY PIRATED COPIES OF SOFTWARE. IT IS SIMPLY A
- DAMAGING PROGRAM DISGUISED AS AN INNOCENT ONE. MANY
- VIRUSES MAYBE HIDDEN IN IT, BUT T.H. THEMSELVES DO NOT
- HAVE THE ABILITY TO REPLICATE.
-
- Viruses also can be spread through a Wide Area network
- (WAN) or a Local Area Network (LAN) by telephone line.
- For example down loading a file from a local BBS.
-
- BBS(bulletin board system)-AN Electronic mailbox that user
- can access to send or receive massages.
-
- However, there seems to be countless numbers of ways to
- become infected. Every-time you down loads a program from
- somewhere or borrowed a disk from a friend, you are taking
- a risk of getting infected.
-
-
-
-
- <4>DAMAGES AND SIGNS OF INFECTION:
-
- a.> Fill Up your P.C. with Garbage:
- As a virus reproduces, it takes up space. This space cannot
- be used by the operator. As more copies of the virus are
- made, the memory space is lessened.
-
- b.> Mess Up Files:
- Computer files have a fixed method of being stored. With
- this being the case, it is very easy for a computer virus to
- affect the system so some parts of the accessed files cannot
- be located.
-
- c.> Mess Up FAT:
- FAT(the File Allocation Table) is the method used to contain
- the information required about the location of files stored
- on a disk. Any allocation to this information can cause
- endless trouble.
-
- d.> Mess Up The Boot Sector:
- The boot sector is the special information found on a disk.
- Changing the boot sector could result in the inability of the
- computer to run.
-
- e.> Format a Disk/ Diskette:
- A virus can simply format a disk as the operator would with
- the format or initialise command.
-
- f.> Reset The Computer:
- To reset the computer, the operator or the user only has to
- press a few keys. The virus can do this by sending the codes
- to the operating system.
-
- g.> Slowing Things Down:
- As the name implies, the object of the virus is to slow down
- the running line of the program.
-
- h.> Redefine Keys:
- The computer has been program to recognize that certain
- codes/ signals symbolize a certain keystroke. The virus
- could change the definition of these keystrokes.
-
- i.> Lock The Keyboard: redefining all keys into an empty key.
-
-
- <5>WHAT TO DO AFTER VIRUS ATTACKS:
- When signs of a virus attack have been recognized,
- the virus has already reproduced itself several times.
- Thus, to get rid of the virus, the user has to hack down
- and destroy each one of these copies. The easier way is to:
-
- 1. Have the original write protected back-up copy of your
- operating system on a diskette.
- 2. Power down the machine.
- 3. Boot up the system from the original system diskette.
- 4. Format the hard disk.
- 5. Restore all back-ups and all executable program.
-
- *If it's not effective, power down and seek for professional help*
-
-
- <6> TYPE OF VIRUSES:
- a.> OVER-WRITING VIRUSES
-
- b.> NON-OVERWRITNG VIRUSES
-
- c.> MEMORY RESENDENT VIRUSES
-
- <7>PRACTICE SAFE HEX:
- Viruses are a day to day reality. Different activities
- leads to different exposure. To protect oneself from a
- virus, several things can be done:
- 1. Avoid them in the first place.
- 2. Discovering and getting rid of them.
- 3. Repairing the damage.
- The simple thing that can cut down on exposure rate are to:
- avoid pirate software, checking programs that have been down
- loaded form the BBS before running them. Make sure that you
- have sufficient backups.
-
-
-
-
- <8> ANTIVIRUS PRODUCTS COMPANY:
- The pace at which new antiviral products have been pouring
- onto the market has accelerated rapidly since the major
- infection of 1988. Indeed, by early 1989, there were over 60
- proprietary products making varied claims for effectiveness in
- preventing or detecting virus attacks.
-
- For: IBM PCs & Compatibles
-
- DISK DEFENDER PC SAFE McAFEE SCAN
- DIRECTOR TECHNOLOGIES THE VOICE CONNECTION McAFEE ASSOCIATES
- 906 University Place 17835 Skypark Circle 4423 Cheeney Street
- Evanston, IL 60201 Irvine, CA 92714 Santa Clara, CA 95054
- TEL: (408) 727-4559 TEL: (714) 261-2366 TEL: (408) 988-3832
- Price: $ 240.00 U.S. Price: $ 45.00 U.S. Price: $ 80.00 U.S.
- Class : HARD.2 Class : SOFT.1 Class: SOFT.3
-
-
- For: Macintosh Plus, SE, & II(Apple)
-
- VIREX
- HJC SOFTWARE
- P.O. BOX 51816
- Durham, NC 27717
- TEL: (919) 490-1277
- Price: $ 99.95 U.S.
- Class : SOFT.3
-
-
- *Class 1(infection prevention class)*
- Most Class 1 products are unable to distinguish between an
- acceptable or unacceptable access to an executable program.
- For example, a simply DOS COPY command might cause the waring
- appear on screen.
- *Class 2(infection detection class)*
- All Class 2 products are able to distinguish all DOS
- commands. Addition to Class 1's prevention fuction, it is able
- to protect all COM and EXE files from infection.
- *Class 3(Top class)*
- Class 3 products are cable of both prevention & detection
- fuctions. And they are cable of removing the infection viruses.
-
-
- <1>. COMPUTER VIRUSES a high-tech disease
- WRITTEN BY: RALF BURGER
- PUBLISH BY: ABACUS, U.S.A
-
- <2>. DATA THEFT
- WRITTEN BY: HUGO CORNWALL
- PUBLISH BY: PONTING-GREEN, LONDON
-
- <3>. COMPUTER VIRUSES,WORMS,DATA DIDDLERS,KILLER
- -PROGRAMS, AND OTHER THREATS TO YOUR SYSTEM
- WRITTEN BY: JOHN McAFEE & COLIN HAYNES
- PUBLISH BY: ST.MARTIN'S PRESS, U.S.A
-
- *************************************************
- * COMPUTER VIRUSES CRISIS * THE SECRET WORLD *
- * WRITTEN BY: PHILP E FITES * OF COMPUTER *
- ****************************** WRITTEN BY: *
- * COMPUTE'S COMPUTER VIRUSES * ALLAN LNNDELL *
- * WRITTEN BY: RALPH ROBERTS * *
- *************************************************