A Computer Cookie is a small data packet or a tiny file that websites store on a user’s computer. Normally, cookies are harmless. The aim of creating website cookies is to enhance the users’ internet surfing experience. Every web browser has an option to enable and disable the cookies. Cookies help websites improve their products and services by remembering the users’ history.
Cookies also track users’ behavior which helps companies show them the most relevant ads. Website cookies are also useful in saving login time by storing the login details of the users. All the website cookies store users’ information in the form of hash data. When data is hashed, only the website it came from can read it. The website uses a unique algorithm to encode and decode the hashed data. If a hacker knows the hash algorithm the website is using, the user’s data can be compromised.
What is Cookie Stealing or Scraping?
Cookie Stealing or Cookie Scraping is also referred to as Session Hijacking or Cookie Hijacking. In this attack, the attacker takes over the user’s session. A session starts when a user logs into a particular service, say, internet banking, and ends when he logs out of it. The attack relies on how much knowledge the hacker has about the users’ session cookies.
Read: Merits and Demerits of Enabling and Disabling the Cookies.
When a user logs into a web application, the server often sets a temporary session cookie in the web browser. This temporary session cookie indicates that the user is currently logged into a particular session. A successful session hijacking cannot be performed unless the hacker knows the victim’s session key or session ID. If he can steal the session cookies, he can take over the user’s session. Another way of stealing the user’s cookies is to force him to click on the malicious links.
Different Methods of Cookie Stealing and Session Hijacking?
Attackers use many methods to steal cookies and hijack user sessions. We list some of the most common methods here.
1] Session Fixation
Session fixation is a type of fishing attempt. In this method, the attacker sends a malicious link to the targeted user via email. When the user logs into his account by clicking on that link, the hacker will know the user’s session ID. He then takes over the user’s session. The entire process of session fixation is as follows:
- A hacker determines that a particular URL, say, HTTP://www.xyz.com/ has no security validation and accepts any session identifier.
- He then sends a fishing email to the user saying, “Hi there, please check out this new feature of our banking app.” On clicking, the link redirects the user to HTTP://www.xyz.com/login?SID12345. Here, the hacker is attempting to fixate the SID (session ID) 12345.
- When the victim logs into the session successfully, the hacker takes over the session and can access the victim’s account.
2] Session Sniffing
In this method, the hacker employs a packet sniffer. A packet sniffer is a piece of hardware or software that helps monitor network traffic. Since session cookies are part of the network traffic, session sniffing allows the hackers to find and steal them easily. What makes the sites vulnerable to session sniffing? When the SSL/TLS encryption is used only on the login pages and not on the rest of the website, hackers can use a packet sniffer to monitor the website traffic and steal the website cookies.
Open Wi-Fi networks are more prone to such attacks because no user authentication is required to connect with them. Hackers can use packet sniffers on public Wi-Fi networks to monitor traffic and steal different users’ cookies. At such Wi-Fi networks, hackers can also perform man-in-the-middle attacks by creating their own access points.
3] Cross-site Scripting (XSS)
In a cross-site scripting attack, the hacker fools the user’s computer system, so that it treats a malicious code secure as it seems to come from a trusted server. When the script runs, the hacker gets access to steal the cookies. When a server or a website lacks essential security parameters, the hackers can easily inject client-side scripts, like JAVA scripts into the webpages. This leads the web browser to execute the code when the user lands on the compromised page.
4] Malware Attack
Hackers can also steal the cookies by malware programs. They develop malware to perform packet sniffing, making it easy for them to steal the session cookies. Malware enters into the user’s computer system when he visits unsecured websites or clicks on malicious links. After entering the user’s PC, it starts searching for the session cookies. When it finds them, it steals and sends them to the hacker.
Read: What are Adware Tracking Cookies?
Why do Hackers want your Cookies?
Hackers always remain in the search of cookies. But the question is, “What do they actually do with the stolen cookies?” We are listing here the top 5 reasons why hackers want your cookies.
1] Cookie Scraping is a Profitable Business
Because cookies contain sensitive information of the users, like credit card details, login details on different accounts, etc., hackers can earn handsome money by selling these details to cybercriminals. They can find cybercriminals easily on the dark web.
2] Stolen Cookies are the Fuel for Identity Theft
When you fill in your details on different online platforms, your information is saved in website cookies. If the hackers are able to steal cookies from these websites, they can perform identity theft. For example, they can take loans in your name or use your credit card for expensive purchases.
3] Hackers can Take Over your Account
You might have seen that when you land on the same website again, like Gmail, Facebook, etc., it already displays your username, and you just have to enter your password. Cookies make internet surfing easier for users by saving their login information. If hackers steal these cookies, they can take over your account and use it for illegal activities. If your account includes payment details, it will cost you a lot.
4] Hackers can use Stolen Cookies to Target Phishing Attacks
Hackers steal users’ personal information by stealing their cookies. They can use this information for phishing attacks, which are fraudulent attempts to obtain users’ sensitive information. Once hackers succeed in obtaining the users’ sensitive information, they can extort them and ask for a significant amount to protect their information from being compromised.
5] Hackers can Harm Companies by Stealing their Cookies
Hackers can also cause financial harm to companies by stealing their cookies. Because cookies may contain companies’ confidential data, hackers can ask for huge money. Sometimes, cybercriminals or hackers can also try to get authorized access to the companies’ networks in order to spy on them or to inject malware.
How can website owners prevent Cookie Stealing?
Being a website owner, you should know the essential tips to prevent cookie scraping.
1] Install an SSL Certificate
There is a continuous data transfer between the user’s web browser and the webserver. An SSL certificate sends this data (cookies) in an encrypted format so that the hacker cannot read it. A website without an SSL certificate transfers this data in plain text. Hackers can easily read this plain text. Therefore, you should always install an SSL certificate on your website.
Read: How to create Self-signed SSL Certificates in Windows.
2] Install a Security Plugin
You should install a WordPress Security Plugin on your website. The security plugin helps protect your website from hacking attempts and also blocks malicious IP addresses. In addition to this, it scans your website regularly and alerts you if any malicious code enters your website. The security plugin provides you with a facility to clean your website instantly. With the security plugins, you can detect hacking attempts and take appropriate action before they cause any harm.
Read: Protect and Secure your WordPress Website from Hackers.
3] Update your Website
Always keep your website up to date. If you have any outdated software or plugins on your website, consider removing them as they may open many vulnerable spots for hackers to steal your confidential data via cookie stealing.
How can website visitors prevent Cookie Stealing?
We are sharing some security tips that help website visitors prevent cookie scraping.
1] Install a Trusted Antivirus
Antivirus software protects your system from phishing and malicious attacks by hackers. It also blocks potentially dangerous websites. You should run a full system antivirus scan regularly to kill all the viruses and malware hidden in your system.
2] Avoid clicking Suspicious Links
Hackers send lucrative offers to their victims via email. These emails contain suspicious links. Never click on such links as your cookie data and personal information may be compromised.
3] Never store Sensitive Information on Web Browsers
Web browsers have an option to save passwords. You should never save your passwords on your web browsers, no matter which browser you use. If you save your password, anyone can log into your account on your system in your absence. Apart from this, hackers may steal your saved passwords.
4] Clear Cookies regularly
Make a habit of clearing the saved cookies before you exit web browsing. Alternatively, you can use private browsing. All web browsers have a private browsing feature. When you surf the internet in incognito, all your browsing history and cookie data will be deleted automatically on exit.
We hope this article gave you sufficient information on cookie stealing or session hijacking. Please follow the remedies listed here to protect your cookie data from being stolen.
