Which type of computer virus attaches itself to executable files and gets activated when the file is run?
File Infector Virus
A File Infector Virus is a type of malicious code that attaches itself to executable program files — commonly files with .exe, .com, .sys, or .dll extensions. The virus code is inserted into the host program in such a way that it is executed first (or alongside the legitimate program) whenever the infected file is run by the user or the operating system.
Once activated, a file infector virus typically follows this cycle:
- Attachment: It embeds a copy of itself into the executable's code, often at the beginning, end, or within unused space of the file.
- Activation: The virus code runs when the infected program is launched, before or after the original program's instructions execute.
- Propagation: It searches for other executable files on the disk (and sometimes on connected/network drives) and infects them too.
- Payload delivery: Depending on how it was written, it may corrupt or delete files, steal data, slow down the system, or simply lie dormant until triggered by a specific date or event.
It is important to distinguish this from other malware types that are frequently confused with it in exams:
| Type | What it infects / how it spreads |
|---|---|
| Macro Virus | Attaches to macros inside documents (e.g., Word, Excel files) rather than executables; activates when the document is opened and macros are enabled. |
| Boot Sector Virus | Infects the boot sector of a hard disk or removable media, so it activates when the computer is starting up, not when a specific program is run. |
| Worm | A standalone program that self-replicates and spreads across networks on its own, without needing to attach itself to any host file or wait for a user to run a program. |
Since the question specifically describes malware that attaches to executable files and activates on running the file, the correct classification is a File Infector Virus, not a macro virus (which targets documents), a boot sector virus (which targets disk boot code), or a worm (which needs no host file at all).
Similar Questions
Which of the following is/are the primary reasons to fall in the trap of Email fraud or phishing?
A) Paying attention to lucrative offers.
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Which of the following is/are the primary reasons to fall in the trap of Email fraud or phishing? A) Paying attention to lucrative offers. B) Not checking on links or attachments from unknown senders C) Providing official information via email D) Paying attention to the company logo sent in the email
Which of the following is/are the primary reasons to fall in the trap of Email fraud or phishing? A) Paying attention to lucrative offers. B) Not checking on links or attachments from unknown senders C) Providing official information via email D) Paying attention to the company logo sent in the email
Which of the following is/are the primary reasons to fall in the trap of Email fraud or phishing? A) Paying attention to lucrative offers. B) Not checking on links or attachments from unknown senders C) Providing official information via email D) Paying attention to the company logo sent in the email
Which of the following is/are the primary reasons to fall in the trap of Email fraud or phishing? A) Paying attention to lucrative offers. B) Not checking on links or attachments from unknown senders C) Providing official information via email D) Paying attention to the company logo sent in the email
Important Questions from Network Security
A ________ is a system designed to prevent unauthorized access to or from a private network.
______ changes each time it is installed to avoid detection by antivirus software.
What is a key security advantage of deploying a DMZ (Demilitarized Zone) using two separate firewalls, rather than a single firewall setup?
Which one of the following is usually used in the process of Wi-fi hacking?
Which of the following is an attack in which the user receives the unwanted amount of e-mails?
