A computer virus infects a computer by attaching itself to legitimate programs, files, or documents and spreading when those infected items are executed or opened by the user. It typically spreads through email attachments, infected software downloads, malicious links, or infected external devices like USB drives. Once activated, the virus can replicate itself across the system, causing damage such as file corruption, stealing information, or slowing down the computer. The virus may remain dormant until triggered by a specific action like opening a file or running a program, which then executes the virus's malicious code and starts the infection process.
How a Virus Infects a Computer
- A virus attaches to software, files, or documents, often hiding inside macros or executable files.
- The user unknowingly executes the virus by opening the infected program, file, or link.
- Once executed, the virus replicates itself, spreading through the computer and connected networks.
- It can spread via email, internet downloads, external devices, or network connections.
- The virus can cause harm, such as stealing data, corrupting files, or sending spam.
Common Infection Vectors
- Email attachments or messages with infected files or links.
- Downloads from untrusted websites or file-sharing platforms.
- Infected USB drives or other removable media.
- Visiting compromised websites with drive-by downloads.
- Exploiting vulnerabilities in software or operating system security.
Virus Lifecycle Stages
- Dormant: Virus lies hidden until triggered.
- Propagation: Virus replicates and spreads copies of itself.
- Triggering: Virus activates when a specific event occurs.
- Execution: Virus runs its harmful code, affecting the system.
Understanding these steps helps in preventing infection by avoiding suspicious emails, downloads, and using reliable security software to detect and stop viruses before they infect a system.
