How Session Hijacking Works and What Businesses Need to Know

Session hijacking is a cyberattack where hackers seize control of your time spent online. By targeting your browser or app after login, they can bypass many security mechanisms we rely on.

Even with authentication protocols or strong passwords, session hijacking can still attack you. For businesses, this can be an alarming thing to discover—customer information can be compromised, accounts can be taken over in an instant, and funds can be transferred without your knowledge. The list goes on and on.

To make matters worse, session hijacking can take many different forms. As such, learning how to detect it is crucial. With that in mind, let’s explore the types of hijacking a business may face. By learning proactive steps, you can even mitigate potential risks moving forward.

What exactly is session hijacking?

We can define a session as the time you spend on a website or application. It usually starts when you authenticate (log in) and ends when you terminate (log out). As such, sessions are unique to every user.

Session hijacking occurs when a hacker targets you after you authenticate your session. Rather than stealing passwords, hackers wait until you’ve logged in before taking control. This allows them to bypass strong security protocols that might be in place.

Below are the common types of session hijacking attacks:

Cross-site scripting

Cross-site scripting (XSS) is one of the most common types of session hijacking. It involves the hacker injecting a malicious script into a legitimate website. When people visit the website, their browser will trust it and execute all scripts.

Unfortunately, the malicious scripts will compromise the user’s security. The hacker can bypass standard security protocols undetected. They can then access the user’s session cookies and seize control.

An example of this kind of attack in action is the popular online game Fortnite. In 2019, it suffered an enormous XXS attack, putting millions of accounts at risk. Players received a link, and if they clicked on it, they were redirected to a website that executed a malicious script. This script immediately stole their usernames and passwords.

Session fixation

In their 2024 data breach report, Verizon found that up to 68% of breaches resulted from social–engineering attacks like phishing. This type of attack involves a hacker building trust with an individual to deceive them into compromising their account.

Session fixation is a form of phishing that targets a person’s session ID. The attack starts when the hacker sends their victim an innocent-looking website link. The victim thinks the link is legitimate and will click on it.

The link will contain a predefined session ID hidden in the URL. When that person logs into their account, the hacker can assume that ID and take control of your account.

Brute-force attacks

Brute-force session hijacking involves the hacker trying to guess session token values. The hacker uses a wide range of common combinations in the hopes of striking luck.

But savvy hackers have some tricks up their sleeves. If a website uses short and predictable values, they can predict new values given to users accurately.

Malware

Malware is any kind of malicious program designed to harm or exploit devices. Modern malware can be undetectable, as it is capable of living in device memory without being installed. As such, it poses an enormous threat to businesses.

In session hijacking, malware can target a user’s browser and disrupt its normal functioning. This type of attack can be used to spy on user activity by recording keystrokes. Additionally, it can redirect users from legitimate websites to fraudulent ones controlled by hackers.

How to prevent session hijacking from taking place

In cybersecurity, prevention is the best form of defense. Below are three effective ways of protecting yourself against session hijacking:

1. Adopt session management practices

There are management practices a business can introduce to prevent session hijacking. Some of the most effective include:

• Strengthening session IDs: Use longer, unique session IDs. This can prevent fixation attacks.
• Analyzing IP addresses: Compare IP addresses of current sessions with previous logins. If there are differences, it could be a cyberattack.
• Implementing session timeouts: This mechanism will revoke a user’s session after a certain time. They will then need to re-authenticate.
• Using proper logout options: Offer definitive logout options. These ensure that every session fully terminates when a user is finished.

2. Use a threat exposure management platform

The dark web is a hidden area on the internet, rife with stolen data. Hackers often share or sell information that can leave a business vulnerable.

Businesses should use a threat exposure management platform for comprehensive session hijacking prevention. This service scans the dark web and can identify stolen session cookies. It can alert you in real time about compromised sessions, thus mitigating damages. With its help, you can revoke all unauthorized access.

3. Avoid using unsecured networks

Unsecured networks like public Wi-Fi are gateways for cyberattacks. They have little to no protection against online activity, and hackers can easily manipulate browser sessions to their liking.

As such, employees should avoid using unsecured networks, especially with work devices. Additionally, consider strengthening your own network’s security protocols to safeguard sensitive work from various common hijacking attacks.

Protecting your business from session hijacking

Session hijacking is a versatile cyberattack. Its ability to go largely undetected makes it a major threat to businesses. As such, you must be proactive to defend yourself against it.

Monitoring online activity is key to detecting suspicious activity. By implementing session management practices, you can protect employees from generic attacks.

Growing businesses should also consider threat exposure management platforms. These can provide real-time protection and alert you to suspicious session activity.