Protecting Your Company From Session Hijacking
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When you perform a task online, like a bank transaction or shopping, you are participating in a web session. This session lasts as long as a user interacts with the web application, which may include being logged in to the web app. Web sessions can be hijacked by cybercriminals who take control of the session data, like a session cookie, to trick the system into thinking this is still an authenticated user performing a task. This type of cyberattack is known as "session hijacking". A recent report by the Cloud Security Alliance found that 73% of session hijacking attacks targeted cloud-based enterprise platforms. The results are costly, with data and identity in the sights of cybercriminals.
What is a Session Hijacking Attack?
OWASP is an industry body that keeps track of cybersecurity threats. They have a section specifically addressing session hijacking. The attack method is described as the "exploitation of a web session mechanism". This definition encapsulates how a cybercriminal intercepts the interactions between a user and a web app to take control. Once the attacker has control, they can use that authenticated interaction to commit fraud, take over accounts, and steal data.
Session hijacking is particularly dangerous as it can be used to bypass multi-factor authentication (MFA). It achieves this by stealing web cookies after authentication has occurred. As such, session hijacking can be described as an identity-based attack. Once the attacker has control of a session token, like a cookie, they have the authentication data needed to bypass some additional identity security layers, like MFA.
Types of Session Hijacking
There are several types of session hijacking attacks:
Predictable Session Token
Session tokens must be generated in a way that makes them unpredictable. If not, a hacker can brute force and hijack a session.
Session Sniffing
Attackers intercept network traffic using network monitoring tools. If a session ID token is unencrypted (for example, it uses an HTTP rather than an HTTPS connection), hackers can steal it and use it to gain unauthorized access to a web server.
Client-Side Attacks
Examples of client-side attacks include cross-site scripting (XSS), malicious JavaScript code, and Trojans. During an XSS attack, a user may click a link that executes malicious JavaScript, which sends the hacker the data within a session cookie.
Man-in-the-Middle Attack (MitM)
A hacker intercepts an unsecured session token and uses it to hijack a session, gaining unauthorized access. Hackers abuse improper encryption protocols to perpetrate MitM attacks.
Man-in-the-Browser Attack
Previously installed Trojan Horse malware compromises the browser's security mechanism. The malware then modifies any transactions via the browser; the user is unaware, as they see the intended transaction.
How Session Hijacking Works
The basic steps to carry out a session hijack are as follows:
- Step one: A user logs into an online account, such as a bank account or e-commerce site. During the login process, a temporary session cookie containing a session ID is generated; this is needed for system functionality and a better user experience. The cookie is stored in the user's browser.
- Step two: A hacker uses one of the session hijacking methods to intercept/steal the session cookie and locate the session ID.
- Step three: The hacker uses the session ID to gain unauthorized access to the account, taking control of the account.
- Step four: The hacker uses the account control to carry out a nefarious act, like fraud, using the account to purchase products, or steal data.
The Costs of Session Hijacking
Session hijacking is a form of identity theft that leads to various forms of cyberattacks.
Data Breaches
Session control provides a road into a broader network. If a session hijacking attack provides control of a user account, techniques like lateral movement can lead to privilege escalation. Once the hacker has admin-level privileges, they can access areas of the network that contain sensitive data. Data breaches cost an SMB an average of $2.98 million.
Unauthorized Financial Transactions and Fraud
A recent cyberattack involved hackers stealing Office 365 user sessions to bypass MFA and commit fraud. One of the outcomes of the attack was the interception of finance-related emails to carry out Business Email Compromise (BEC) scams. A report from Osterman found that BEC scams cost a company, on average, $137,132.
Identity Theft and Account Takeover (ATO)
Identity theft and account takeovers (ATOs) can lead to the loss of sensitive data, fraud, operational disruption, and reputation damage. Research from analyst firmJavelin Strategy & Research found that identity fraud costs US businesses $23 billion. A recent industry report found that 73% of users believe a brand is responsible for preventing ATOs.
Regulatory Noncompliance Violations
Data theft, privacy violations, fraud, and other nefarious acts committed during session hijacking attacks leave a business open to various regulatory noncompliance fines.
Reputation Damage
The FBI published a warning about a spate of ongoing Zoom-bombing attacks. The attackers used session hijacking to initiate the infiltration of the video meetings. These types of infiltration attacks can impact a company's reputation and provide attackers with knowledge of company secrets that can then be used to extort company funds.
How To Protect Your Business From Session Hijacking
Session hijacking comprises various types of techniques. To protect your business from this type of attack, you must put multiple layers of measures in place, including the following:
Encryption
Enforce encryption of session tokens by implementing the standard Internet Protocol TLS (Transport Layer Security). Also, use data at rest encryption, like database storage encryption, for stored data.
Robust Session Management
Put measures in place to handle sessions, for example, enforce active sessions expiration after a defined period of inactivity.
Secure Cookies and Session IDs
Set the "secure" flag on cookies containing session IDs to prevent transmission over unencrypted HTTP connections.
Robust Authentication and Risk-Based Authentication
MFA can be bypassed using session hijacking. To improve the robustness of your authentication measures, explore the use of biometric or Passwordless (FIDO) based measures and protocols.
Content Security Policy (CSP)
A CSP helps to prevent XSS-based session hijacking attacks. OWASP provides further details on CSPs.
Educate Employees
Phishing and insecure internet use can open doorways for session hijacking attackers. Educate all employees about safe internet use, such as using a VPN and logging out of sessions. Provide phishing education and phishing simulations to help employees recognize the signs of phishing attacks.
FAQs
Is Session Hijacking the same as Token Replay Attacks?
Session hijacking and Token Replay attacks are similar but different. Session hijacking intercepts an active session between a user and a web server by stealing the session ID or session cookies. Token Replay attacks reuse already intercepted data. Both attacks can result in unauthorized access to user accounts and sensitive data.
What are the Signs of a Session Hijacking Attack?
Signs you may be a victim of session hijacking include unusual account activity, alerts showing simultaneous logins, and suddenly terminated user sessions. Analysis of network traffic and system logs can be used to detect signs of session hijacking.
How Do You Prevent Session Hijacking?
Session hijacking may involve multiple techniques and tactics, so a company must respond using layers of security measures, including encryption, secure cookies, employee security education, and a Content Security Policy (CSP).