COMPUTER VIRUS :

  • 1. Boot Sector Virus

    • The Analogy: Imagine a virus that infects the ignition key or the starter motor of your car.

    • How it works: It hides in the Master Boot Record (MBR). The moment you switch the computer on (during booting), the virus activates before anything else even loads.

    • Example: Disk Killer or Brain.

  • 2. Program or File Virus

    • The Analogy: Imagine a cold virus that hitches a ride inside a specific app on your phone, like a mobile game.

    • How it works: It attaches itself to executable files like .exe or .com. The virus sits completely quiet until you click and run that specific program. Once opened, it jumps into the computer's memory and infects other apps.

    • Example: Jerusalem or Cascade.

  • 3. Polymorphic Virus

    • The Analogy: Think of a shapeshifting thief who changes their clothes, hair color, and face masks every single time they break into a room.

    • How it works: "Poly" means many and "morph" means form. Every single time this virus makes a copy of itself, it alters its digital signature (code structure). Because it constantly changes its appearance, security guards (Antivirus software) have a hard time recognizing it.

    • Example: URSNIF or VIRLOCK.

  • 4. Macro Virus or Document Virus

    • The Analogy: Imagine opening a birthday card, and a spring-loaded clown suddenly pops out at your face.

    • How it works: It hides inside automated scripts (macros) embedded inside data files like Microsoft Word documents or Excel spreadsheets. The virus remains completely dormant until you physically double-click to open the document.

    • Example: Melissa.

  • 5. Multipartite or Hybrid Virus

    • The Analogy: A coordinated double-attack where one intruder breaks through the front door while another slips through the basement window at the exact same time.

    • How it works: It is a combination attack. It targets both the system's hard drive (boot sector) and individual program files (.exe) at the same time. Because it spreads through multiple pathways simultaneously, it causes massive damage and is very difficult to clean out completely.

    • Example: Natas or Tequila.