male hacker using session hijacking

What is Session Hijacking?

Session hijacking is a form of cyberattack where an unauthorized individual gains access to a user’s session on a web application or website. This allows the attacker to take control of the user’s account and potentially access sensitive information.

Why is this important to you? Session hijacking can have serious consequences for both individuals and organizations. For individuals, it can result in identity theft, financial loss, and privacy breaches. For organizations, it can lead to data breaches, compromised networks, and damaged reputations. Understanding how session hijacking works can help any web user protect themselves from these risks.

What Are Sessions?

Sessions are temporary storage areas that contain data related to a user’s activity on a website or web application. When a user logs into a website or web application, a session is created and assigned to that user with a unique session ID granting access to important information like the user’s login credentials and browsing history.

Think of it like a room where you store valuable information. Without sessions, you would have to log in to the same website every time you click on a new page, like having to undo a complicated series of locks every time you enter your room. With sessions, you can simply use your ID to leave the door unlocked, allowing you to pass in and out freely until you decide to end the session.

What Is Session Hijacking?

Session hijacking is when a hacker gains control over a user’s session without their knowledge, usually to steal sensitive information or manipulate the user’s online activity.

Sources of Session Hijacking Attacks:

  • Side jacking (aka Man-in-the-Middle attacks): The hacker intercepts network traffic between a user and a website, allowing them to steal session cookies and access the user’s data.
  • Cross-Site Scripting (XSS): By injecting malicious code into a website, attackers can exploit vulnerabilities in the web to gain access to sensitive information or manipulate user activity.
  • Hijacking through malware: Malware is malicious software that can infect a user’s device and give hackers remote access to their system, including their session data on various websites.
  • Session fixation: The hacker tricks a user into using a session ID that they have previously obtained or created, allowing hackers to access the session and take control of their account.
  • Session key prediction: Hackers can use various techniques to predict or generate valid session IDs (that’s why unique passwords matter), allowing them to hijack active sessions on websites.

How Does It Work?

It works by exploiting vulnerabilities in web applications or using social engineering techniques to gain access to a user’s session. Let’s dive into some details.

Where Does It Usually Start?

Attackers often use phishing emails, which look like legitimate messages containing links from reputable websites, such as a OneDrive share link or an invoice from a well-known company. By tricking users into clicking on these links, attackers can gain access to their sessions.

Specific groups may also be targeted at busy times of the year. For example, hackers may target accountants during tax season, nonprofits receiving donation-related emails, or businesses receiving invoices—all during times when they’re the most busy and likely to click on an innocent-looking link without thinking twice.

How Does the Attacker Gain Access? 

Once the user clicks on a malicious link, the hacker can use different methods to gain access to their session. These may include stealing session cookies, exploiting vulnerabilities in the web application’s code, or using malware. Once a hacker has the session ID, you don’t even have to enter your credentials for them to have access to your accounts.

What Can the Attacker Access?

By gaining control of a user’s session, attackers can access sensitive information such as login credentials, personal information, and financial data. This includes email accounts, online banking, social media profiles, and any other services or applications the user has accessed using that session.

The more interconnected our digital lives become, the more vulnerable we are to this type of hijacking. Single Sign-On (SSO) platforms like Microsoft, Dropbox, and Octa mean that hackers obtaining a single password could have devastating results. If you use SharePoint, they can access all your data in SharePoint. If you are a M365 admin, they can access the contents of all your users’ mailboxes, too.

The Impact of Session Hijacking

The consequences of a successful session attack can be severe. For individuals, it can lead to identity theft, serious financial loss, and loss of privacy. In some cases, personal information may also be used for malicious purposes such as blackmail or extortion.

For organizations, the stakes are even higher. Data breaches can lead to compromised networks, financial extortion, business shutdown, loss of valuable or protected data, and even legal consequences, not to mention damage to their reputation.

Prevention Measures

As with any cyberattack, prevention is always better than dealing with the consequences. Here are some measures you can take to protect yourself and your organization from a session hijack:

1. Checking URLs When Clicking Links

Be cautious when clicking on links, especially if they are from unknown sources. And since phishing emails often contain fake URLs that mimic legitimate websites, it’s crucial to double-check the URL before clicking.

2. Caution After Clicking URLs

Even if a login page looks legitimate, never enter your credentials without verifying that the website’s address is correct even after you’ve clicked. If you get an authentication request you don’t expect after clicking on a click, it may be a sign that something is wrong.

3. Use Microsoft  365 Manage Detection and Response (MDR)

Microsoft 365 MDR is incredibly helpful in detecting and preventing session hijacking. MDR monitors your network for suspicious behavior and responds to cyber threats in real time, providing an extra layer of security for your organization.

4. Session Timeout and Expiry

Implementing a session timeout mechanism or restricting the lifetime of sessions can help decrease the vulnerability window for attackers. This means that even if someone gains control of a session, it will automatically expire after a certain period and require reauthentication.

Myth: MFA Provides Full Protection

Multi-factor authentication (MFA) is designed to protect against cyberattacks by requiring both a password and another form of authentication (such as a code sent to your phone) before accessing sensitive information. So if you have MFA, you should be safe, right?

The truth is, MFA alone doesn’t guarantee complete protection from session hijacking. If an attacker has an active session ID, they don’t actually need to know passwords or MFA details to access your data as long as the session lasts, which could be several weeks. In this case, MFA provides a false sense of security, and additional measures should be taken to prevent attacks.

Comprehensive Cybersecurity With Run Networks

Staying safe from such complex cyber threats can be daunting, but don’t let that stop you from taking action. At Run Networks, we offer comprehensive cybersecurity solutions, including Microsoft 365 MDR, to protect your organization from session hijacking and other cyberattacks.

Our team of experts utilizes the latest technology and strategies to keep your network safe and secure. Don’t wait for a cyberattack to happen—take proactive measures today with Run Networks. Contact us today to get a network evaluation and see how we can help secure you and your organization.