Supercookies are a serious threat to internet privacy. They are not stored on your computer but can identify your web traffic and are tremendously tough to detect. You would have heard of “Cookies”, no not the sweet edible ones, but we are talking about computer cookies that track you while you are browsing on the Internet. In simple terms, cookies are text files with pieces of information about your online activity.
Talk about an HTTP cookie which is again a small piece of code that is left in your web browser by a website that you visited. This cookie places info on your device so that the website could identify you as a returning user later when you visit it again. So, now when you have understood Cookies, let’s deep dive a bit further and know how Cookies work and the phenomenon called as Supercookies.
Understanding Cookies in detail
Most PC users accept that websites will download “Cookies” from the computer systems after they have visited the website. These browser-based files carry basic information that makes web browsing an easier and faster experience with successive site visits. Though their operation is somewhat fishy, most of the cookies are harmless and contribute positively towards enhancing your browsing experience. They store information that reduces loading times on different pages.
Let’s take an instance of you visiting an e-commerce website for some online shopping. You logged in, added items to your digital cart, and then decided not to buy anything until few days. Now, when you logged back to the same website after a few days you would see that you are still logged into the site and all the items that you added earlier are safe in your digital cart. Here, the dogged login and stored cart items are recorded onto a cookie file that the website quickly reads as you visit the website again. So, cookies help in improving your browsing and shopping experience.
Now, browser cookies are also of different types, and it has to keep in mind that not all cookies are made to tamper with your online security but are instead beneficial. Here are some of the common browser cookies.
- HTTP-only cookies help in reducing a cookie’s vulnerability to a cross-site scripting (XSS) attack
- Flash cookies ( a type of supercookie )
- Third-party cookies that originate from a third domain and are categorized as harmful
- First-party cookies are also known as permanent cookies, they help sites to remember user’s information and settings when they revisit them in the future
- Session cookies are best known as website’s short time memory
- Secure cookies that can only be transmitted over an encrypted connection
- Zombie cookies are closely related to flash cookies and can instantly recreate themselves if someone deletes it
Few cookies are removed after a few days or are coded to automatically delete after a fixed time period, these are persistent cookies. Then there are Supercookies that are tough to delete as these are designed to evade deleting capabilities in common browser cookies. Let learn more about them.
What are Supercookies?
The terms “supercookies,” “permacookies,” or “zombie cookies”—as these trackers are commonly referred to—are not cookies at all.
A supercookie is a tracking cookie but has a more threatening use. Supercookies have completely different functionality to a normal cookie. It is a type of tracking cookies that are inserted into an HTTP header by an internet service provider (ISP) that gathers data about a user’s internet browsing history, habits, and preferences. Also known as a Unique Identifier Header (UIDH), a supercookie is not an HTTP cookie in technicality, but rather information injected into packets sent from a user’s device and the service it connects to. So, when the ISP spots a user’s HTTP traffic it inserts an extra HTTP header into the packets after they leave the user’s computer.
Supercookies can be used to gather an extensive range of data on users’ personal internet browsing habits and preferences including the website’s users prefer visiting and the time they are visiting. And, it doesn’t matter which browser is being used or if the user switch browsers. Supercookies are also apt to access and collect information from traditional tracking cookies; these include login information, plug-in data, cached images, and files. It can store that information even after the traditional cookie has been deleted.
Why Supercookies are lethal
With a normal cookie, you can restrict it to follow you around the internet by simply clearing the browser data, cookies, and more. Cookies and third-party cookies can be blocked from the browser through settings, they can also be auto-deleted once the browser session ends. But a supercookie is completely different – Clearing or deleting browsing data does not help. This is because a supercookie is not a real cookie and it’s not stored in the browser but it’s injected between the device and the server it’s connecting to. Simply put, these are different from traditional cookies, they are harder to detect and get rid of because many of them don’t exist on your computer or in normal cookie storage locations. And there is not much a user can do about it.
Supercookie is not a cookie and it is not saved in your local stores like normal cookies. Instead, they are injected by the Internet Service Provider (ISP) and it appears between your network and the server of the HTTP site. They can easily gather the user’s login credentials, plug-in data, image, and file caches.
Supercookie is a tracking cookie that you are nearly impossible to remove. Unfortunately, they cannot be cleared by deleting browser cache data. Nor can adblockers or privacy trackers block them. Users can opt-out if their ISP allows.
The dangers of Supercookies
Verizon, the largest US wireless carrier by subscribers, was hit with a $1.35 million fine by the US Federal Communications Commission for its use of “supercookies” that track users’ web browsing activity without their knowledge.
Clearly, Supercookie is a form of a privacy breach. Traditional cookies are tied only to a single website and cannot be shared with another site, but UIDH can be disclosed to any website and contain a huge amount of potential information about the user’s habits and history. Supercookie can be damagingly used to collect a lot of data and then resell it.
The Electronic Border Organization (EFF) also states that supercookies can be used by advertisers to essentially recover deleted cookies from user devices and link them with a new strategy, evading the preventing strategies taken by the users. Also, EFF notes that UIDH can also apply to data sent from applications. This combination allows creating a detailed picture of the user’s internet usage habits.
Read: What are Browser Independent Cookies?
How to remove a Supercookie
By now we understand that Supercookies stores a lot of information about users. Some of them can recover common deleted cookies and some may not be stored on your device. So, what can be done to remove it? There is very “little” a user can do to know or prevent a site from using Supercookies because tracking happens “behind the scenes”.
Supercookies hinge on HTTP connections, hence, making an encrypted connection with a website breaks tracking headers from functioning. Visiting only HTTPS websites including those that use TLS or SSL certificates helps in avoiding Supercookies from tracking the user’s activity or catching them. Also, you can redirect your internet traffic through a secure network- it’s best to use a VPN to create an encrypted connection between you and the rest of the internet.
Firefox, Chrome, Edge, Safari, and other browsers are cracking down on supercookies.
Lastly, as a general use the best browser security tools for the best security applications. Using HTTPS and VPN may be a useful option, but in the end internet users need is a strong law that requires ISPs to allow the users to reject such programs that track their internet footprints.