What is a Session?
A web session refers to a series of user interactions with a website or web application within a given time frame. Each web session is classified with a unique IP address. Web traffic is the measure of the number of user sessions on a site. Therefore, a greater number of web sessions means high traffic. The converse also holds.
Web sessions include search engine searches, a site visitor filling out a form, adding items to a shopping cart, and completing eCommerce transactions. Web sessions are usually prone to session hijacking attacks. This article explains what session hijacking is, how it happens, the examples of session hijacking, consequences, and prevention techniques.
What is Session Hijacking?
Session hijacking, as the term suggests, is when a hacker hijacks a user on a session. One of the most common forms of Man in the Middle attack gives a hacker complete control over a users’ session and online accounts.
A session hijacking attack relies on the hacker’s knowledge of your session cookie. As such, this attack is frequently referred to as cookie side-jacking. Usually, when visiting a website or logging into a web application, the server will have to set an impermanent session cookie in the users’ web browsers. The session cookie helps the server to remember that a user is currently logged in and authenticated.
How is a Session Hijacked?
The following are the steps to session hijacking:
Step 1: An unsuspecting website or web application user logs into an online account. For instance, an account owner might log into their bank account, or a web visitor might visit an online store to shop around. Once the user visits the website or web application, the application or website will install a temporary session cookie in the application or browser. The cookie session carries details about site visitors, allowing a site or application to keep the users logged in and authenticated. The cookie will also track the users’ activity over the session. The session cookie will stay active until the user logs out.
Step 2: A hacker Accesses a Valid Session: Hackers have crafted different techniques they use to steal valid sessions. They will grab a valid session cookie, find the session ID within the cookie, and use these details to control the session fully. When a hacker gets hold of a session ID, they can fully control a session without being detected.
Step 3: With a valid session key and full control over a session, the session hacker now gets a payoff for hijacking a session. Once the valid user exits, the attacker now uses the ongoing session to commit a series of despicable acts. For instance, the hijacker can transfer money from the users’ account to their account, purchase items from an online store, commit identity thefts using users’ personal data, and commit ransomware attacks. All these could leave a user devastated, so a user must know how to prevent a session hijacking attack.
Examples of Session Hijacking
Check out the two scenarios below:
Brian is sitting at a restaurant, sipping his favorite drink while browsing through his money market account. Brian uses the restaurant’s Wi-Fi to browse. Unfortunately, a session hijacker is seated at the next table. The hijacker uses the session sniffing technique to grab the session cookie, take control of Brian’s account, transfer funds to unknown accounts, and use Brian’s sensitive information for malicious purposes.
Nancy receives an email from someone purporting to be her favorite retailer. Nancy is convinced that she would receive a commission for purchasing one of her favorite products. What she does not know is that the email is a phishing scam from a hacker. She goes ahead to click a link that carries a hacker’s session key. The hacker hijacks Nancy’s session goes on a shopping spree and pays for the products using Nancy’s credit. Nancy later realizes it’s too late, and she does not know how to stop malware attacks, phishing attacks, or other forms of social engineering attacks. She has fallen victim to a session hijacking attack.
How to Prevent Session Hijacking
A State of art Survey on session hijacking reveals that ordinary users and administrators have little knowledge about session hijacking. Additionally, both categories do have a clear understanding of how to prevent session hijacking attacks. The graph below illustrates this.
There are several measures that you can take to protect yourself from session hijacking attacks.
- Avoid Using Public Wi-Fi to Browse Through Sensitive Accounts
Never should you use public Wi-Fi to access sensitive accounts such as your bank accounts, employee portals, social media accounts, email accounts, or eCommerce accounts. Like in Brian’s case, there might be a session hijacker at the next table who uses packet sniffing to try and grab your session cookies. Public Wi-Fis are susceptible to hacking, and you must avoid them.
- Check Security of a Website before Using the Website
Reputable banking institutions, genuine emails, and eCommerce websites have appropriate measures to prevent session hijacking attacks. For example, websites should have SSL certificates, undertake regular site audits, and use firewall protection. Sites that do not have such tools will remain susceptible to session hijacking.
An SSL certificate encrypts the in-transit communication exchanged between the web browser and the client-server when installed on your website. This protects the customers’ PII from falling into the hands of hackers with malicious intentions.
- Use a Virtual Private Network
A Virtual Private Network will help you browse safely by keeping session hijackers far away from your session. A VPN masks your Internet Protocol address and ensures that all your activities are kept private.
A VPN creates a private tunnel that allows for the safe transfer of data and all private activities to achieve this. It also encrypts sensitive data, thus protecting it from hackers and session hijackers.
- Protect Against Malware Attacks
Nancy became a victim of session hijacking because she responded late and did not know how to stop malware attacks. Like in her case, hackers can send you malicious links. Upon downloading such links, you become easy prey to session hijackers. Therefore, you must install antimalware software and know other measures to protect yourself against malware attacks.
The thought of falling victim to a session hijacking can be so terrifying. However, you should know what a session hijacking is, how it is done, and some of the measures you should take to protect yourself. This article covers all that.