A zombie cookie is not something like a typical website cookie designed to enhance the user experience. These tricky third-party cookies can also come back to life even after you delete them as if they can’t be deleted permanently. Zombie Cookies look like something out of a malicious practice done for some specific reason. So let’s take a look at how they work, how to spot them, and whether there’s a way to kill them permanently.

What are Zombie Cookies?

Zombie cookies are a type of online tracking tool that is very difficult to remove. Unlike regular cookies, which you can delete from your browser settings, zombie cookies come back to life even after you delete them. They are used to track your online activities and gather information about you. Zombie cookies are a stubborn tracking mechanism that can repeat even after they have been deleted. They pose a serious privacy risk because they can reappear without the user’s consent, making it difficult to maintain confidentiality.

It is a type of cookie that can recreate itself after being deleted. They are stored in multiple locations, such as Flash storage, HTML5 Web Storage, and other hidden locations, making them hard to remove completely. These cookies are often used for tracking purposes, violating user privacy.

How Do Zombie Cookies Work?

Zombie cookies work by using backup storage locations on your computer or device. Even if you delete a cookie from your browser, you can restore it from these backups. It can be stored e.g. Flash storage, HTML5 web storage e, or maybe another browser.

• Initial storage: Zombie cookies are first stored in a common location such as a standard HTTP cookie.
• Storage Location: Some of these cookies are stored in other locations such as Flash Local Shared Objects (LSOs), HTML5 Local Storage, or ETags.
• Reproduction mechanism: When a user deletes a cookie, the browser retrieves it from a backup location, effectively “resuscitating” the cookie.

Because of the rigid nature of zombie cookies, your online behavior can be continuously monitored without your knowledge or consent.

Why are Zombie Cookies a Problem?

Zombie cookies are a problem for several reasons:

• Invasion of privacy: Your online activities are monitored without your permission.
• Difficult to remove: Designed to be difficult to delete, making it difficult to protect your privacy.
• Data collection: Companies may collect detailed information about your browsing habits, which can be used for targeted advertising or to sell to third parties.

How to Block Zombie Cookies

Methods to Block Zombie Cookies:

1. Disable Third-Party Cookies

Most zombie cookies come from third-party advertisers. Disabling third-party cookies in your browser settings can prevent them from being set at the beginning.

Example:

• In Chrome: Go to Settings > Privacy and Security > Cookies and other site data > Block third-party cookies.
• In Firefox: Go to Preferences > Privacy & Security > Cookies and Site Data > Block cookies and site data (may cause websites to break) and select All third-party cookies.

2. Use Private Browsing Mode

Private browsing or incognito mode does not store cookies after the end of its use, it provides an extra layer of protection against zombie cookies.

Example:

• In Chrome: Open a new Incognito window by clicking on the three dots in the upper right corner and selecting New Incognito Window.
• In Firefox: Open a new Private Window by clicking on the three horizontal lines and selecting New Private Window.

3. Install Privacy-Focused Browser Extensions

Extensions like Privacy Badger, uBlock Origin, and Ghostery can block tracking cookies, including zombie cookies.

Example:

• Install Privacy Badger from the Chrome Web Store.
• Once installed, Privacy Badger will automatically start blocking trackers on websites you visit.

4. Clear Supercookies

Supercookies can store data outside regular cookie storage. Use browser settings to clear these types of cookies.

Example:

In Firefox: Go to Preferences > Privacy & Security > Cookies and Site Data > Clear Data, and check both Cookies and Site Data and Cached Web Content.

5. Manage Flash Cookies

Adobe Flash Player stores cookies that can respawn deleted HTTP cookies. Disable or manage these cookies through the Flash Player settings.

Example:

• Access Flash Player settings by going to the Flash Player Settings Manager on Adobe’s website.
• Disable third-party Flash content storage.

6. Regularly Clear Cookies and Cache

Regularly clearing your browser’s cookies and cache can help remove zombie cookies.

Example:

• In Chrome: Go to Settings > Privacy and Security > Clear browsing data, select Cookies and other site data and Cached images and files, and click Clear data.
• In Firefox: Go to Preferences > Privacy & Security > Cookies and Site Data > Clear Data, and select Cookies and Site Data and Cached Web Content.

7. Use Anti-Zombie Cookie Scripts

Certain scripts can detect and delete zombie cookies across all storage locations.

Can You Turn Off Zombie Cookies?

Blocking zombie cookies can be difficult, but it is possible with the right tools and practices. Here are some takeaways.

• Use a privacy-conscious browser: Browsers like Firefox and Brave provide good privacy protection and can help prevent zombie cookies.
• Install privacy extensions: Browser extensions like Privacy Badger, uBlock Origin, and Ghostery can help detect and block trackers with zombie cookies.
• Disable Flash Storage: Since zombie cookies often use Flash storage, it can be helpful to enable or disable Flash. Most modern browsers are phasing out Flash support.
• Clear your browser data regularly: Clear your browser cache and cookies regularly. Al, so use tools that delete Flash cookies and other hidden storage areas.
• Use a Virtual Private Network (VPN): A VPN can mask your IP address and encrypt your Internet traffic, making it harder for trackers to track.
• Stay up-to-date: Stay up-to-date with the latest tools and techniques to protect yourself from new surveillance techniques.

Conclusion

Zombie cookies are persistent and aggressive tracking tools that can reappear even after deletion. They pose a serious threat to Internet privacy. While it can be difficult to block them completely, using a privacy-conscious browser, installing extensions, and cleaning your data regularly is crucial in the fight against zombie cookies therefore knowing the latest privacy trends can help protect your privacy and reduce tracking.

What are Zombie Cookies, and Can You Block Them? -FAQs

What do zombie cookies do?

Zombie cookies, also known as evercookies or supercookies, are tracking files that users use to delete even browser cookies to collect website user data These cookies are stored in multiple locations, making them difficult to remove from the source.

What happens if you don’t accept cookies?

A potential problem with refusing to accept cookies is that some website owners may not allow you to use their website if you do not accept their cookies. Another downside is that without permission, you may not get the full user experience on some sites.

Should I block all cookies?

If you block all cookies, there are a few downsides. You won’t be able to hide items in the shopping cart between sessions, you can access websites every time you open and close a browser, and you may not get customized ads, but you will see irrelevant ads more often.