Diagnostic software

Virus detection/Protection


A virus is a loose term used for all malicious software.
mal-ware includes:
Virus
Trojans
Worms
Hoaxes
Logic bombs
Back doors



What Is A Virus
A peioce of code that isnderts itself into another program and modifies its operation.  Reqiures the Infected program to be passed to another system and be excuted to spread.  Virus have two phases.  
- Infection Phase : The active virus seeks  out and infects new host program.
- Attack Phase : after a trigger event the  payload is released.  Trigger event provides time for infection to spread.
- Payloads : humorous, harmless, Hoax, Dataa Destruction, O/S corruption.

Virus Features.
- Small: Has to fit inside another program..  Has To be TSR (Terminate and Stay Resident)

Virus Catagories(types)
- Boot Sector: Infects MBR code.  not removved by formatting HDD. Use FDisk /mbr .  MBR on floppies executes even if Floppy is non-system.
- EXE Virus : Virus that infects executablee programs.  .com, .exe, .sys, .ovl, .dll, ...
Macro Virus : writen in VB inside word and office documents.


NOT A VIRUS!!!
- Trojan : look like one porogram, but do ssomething else.
- Haox : Message or program that tells you  to do something wrong/harmfull.
- Back Doors : open your system up for remoote access.  requires trojan or dropper program to deliver


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