TL;DR
Yes, computer viruses aren’t limited to hiding on your hard drive. They can live in many places – removable drives (USB sticks), email attachments, network shares, even within other programs or the system memory while running. Protecting yourself means being careful about what you open and where you get it from.
Where Viruses Hide: A Step-by-Step Guide
- Hard Drive (The Usual Suspect)
- Viruses often attach themselves to legitimate files on your hard drive.
- They can also hide in folders, system files, and the boot sector of the drive.
- Removable Drives (USB Sticks & External HDDs)
- Viruses spread easily via USB sticks. When you plug one in, the virus can automatically copy itself onto your computer.
- Always scan removable drives with an antivirus program before opening any files on them.
- Email Attachments
- A common way viruses get in! Never open attachments from unknown senders, and be cautious even with known senders if the attachment seems unusual.
- Look for suspicious file types (e.g., .exe, .scr, .vbs) – these are often used to deliver malware.
- Network Shares
- If you share folders on your network, a virus can spread through those shares if someone with an infected computer accesses them.
- Ensure strong passwords and restrict access to only trusted users.
- Downloaded Software
- Downloading software from untrusted sources is risky. Viruses can be bundled within the installation files.
- Only download software from official websites or reputable app stores.
- Within Other Programs (Trojan Horses)
- A Trojan horse disguises itself as a legitimate program, but secretly contains malicious code.
- Antivirus programs can detect and remove Trojans before they cause harm.
- System Memory (RAM)
- Some viruses can load themselves into your computer’s RAM while it’s running, making them harder to detect.
- A full system scan with an updated antivirus program is crucial for finding these types of threats.
- Web Browsers (Browser Extensions/Add-ons)
- Malicious browser extensions can install viruses or track your activity.
- Only install extensions from trusted sources and regularly review the extensions you have installed.
How to Protect Yourself
- Install Antivirus Software: A good antivirus program is your first line of defence. Keep it updated!
- Keep Your Operating System Updated: Updates often include security patches that fix vulnerabilities viruses can exploit.
- Be Careful What You Click: Avoid clicking on suspicious links or downloading files from unknown sources.
- Regularly Scan Your Computer: Schedule regular full system scans with your antivirus program.
- Use a Firewall: A firewall helps block unauthorized access to your computer. Windows has a built-in firewall, but you can also use third-party options.