TL;DR
Cookies themselves cannot carry viruses. However, they can be used by malicious software (like malware) or websites to track you and potentially steal information. Keeping your browser updated, using strong security software, and being careful about the sites you visit are key.
Understanding Cookies
Cookies are small text files that websites store on your computer. They remember things like your login details, shopping cart items, or preferences. They’re designed to make your browsing experience smoother – they don’t have the ability to execute code and therefore can’t directly infect your system.
Why the Confusion?
The idea that cookies carry viruses comes from a misunderstanding of how malware works. Viruses are programs that replicate themselves and spread to other files or computers. Cookies aren’t programs; they’re just data.
How Cookies Can Be Part of a Problem
- Tracking: Cookies can track your browsing activity across different websites. This information is often used for targeted advertising, but it can also be exploited by malicious actors.
- Session Hijacking: If a cookie containing your session ID (a unique identifier that keeps you logged in) is stolen, someone else could potentially access your account.
- Cross-Site Scripting (XSS): A compromised website can inject malicious code into cookies, which then gets executed when you visit the site. This isn’t a cookie problem directly, but it uses cookies as a vehicle for the attack.
- Malware Assistance: Malware already on your computer could use cookies to store information or help with its operation. The cookie isn’t *causing* the infection; it’s being used by something else that is.
Protecting Yourself
- Keep Your Browser Updated: Browser updates often include security patches that address vulnerabilities exploited by attackers. Check your browser settings for update options. For example, in Chrome:
- Click the three dots (menu) → Help → About Google Chrome
- Use a Reputable Security Suite: Anti-virus and anti-malware software can detect and remove malicious programs that might try to use cookies.
- Be Careful What You Click: Avoid clicking on suspicious links or downloading files from untrusted sources.
- Clear Your Cookies Regularly: This removes tracking data and reduces the risk of session hijacking. Most browsers allow you to clear cookies in their settings.
- Chrome: Settings → Privacy and security → Clear browsing data
- Consider Browser Extensions: Some extensions can block tracking cookies or enhance your privacy.
- Enable ‘Third-Party Cookie Blocking’: This prevents websites other than the one you’re currently visiting from setting cookies on your computer. Settings vary by browser, but it’s usually found in the Privacy and Security section.
- Firefox: Settings → Enhanced Tracking Protection
Checking for Suspicious Cookies (Advanced)
You can manually inspect cookies stored by your browser. This is more technical, but it can help identify potentially malicious ones.
- Chrome: Press F12 to open Developer Tools → Application → Storage → Cookies
- Look for cookies with unusual names or domains.
In Summary
While cookies aren’t viruses, they can be exploited in various ways. By following the steps above, you can significantly reduce your risk and keep your browsing experience safe.