How Hackers Can Steal Credentials with Session Hijacking
By Nick Anderson 4 minutes
Hackers are not just fictional characters created to give movies a plot, they are very much a threat, moreso than ever before as the digital revolution is bringing more devices and users online. To that end, we are bringing your attention to another vulnerability that exists and is exploitable.
What is a Session?
Internet communication is based on a series of exchanges. The first steps towards communicating with a web server is knowing the right address. The web server serves millions of clients, so it needs to identify you in order to server you a webpage, often one that’s unique for you.
This is done by generating a token that is unique to you and the session. A session is the duration of your communication with the web server. HTTP (Hyper-text Transfer Protocol) is used for web communication, and because it is a stateless protocol, sessions need to be established that can uniquely identify users among the several other TCP connections.
A session is initiated when a web server authenticates you. When you log-in to your bank account or ecommerce platform account, a session is initiated and remains active until you log out, or if you remain inactive for some time.
How Sessions can be hijacked
Sessions can be hijacked in a number of ways. The attacker can sniff data packets flowing between you and the web server and steal the session ID. This is possible on vulnerable Wi-Fi networks such as on public Wi-Fi hotspots. If there is no encryption between the client and web server, an attacker can initiate a Man-in-the-Middle attack by sniffing on the communication, steal the credentials and session ID, then impersonate you on the web server.
Another method involves injecting malicious scripts on your web browser. The attack doesn’t orginate at the client-side but at the server-side. This is known as Cross-site Scripting (XSS).
When a user uses a website that has been compromised by a vulnerability or the attacker lures you into clicking a link, the attacker can issue a code to your web browser that then executes at your side. The purpose of the attack is to steal browser cookies that contain session information.
Session IDs are generated randomly using algorithm. It is possible for an attacker to predict and generate a Session ID using brute forcing if there is a weak algorithm. This method can be used to predict your active session key.
How to Prevent Session Hijacking
There some measures you can take to prevent falling victim to loss of personal or financial information.
Firstly, you must always use https version of websites. It is a secure version of the http which uses encryption to secure communication between the client and server. Most websites today use https communication which you can confirm by checking the green padlock in the URL of the web browser. But, unfortunately, many websites don’t or don’t direct the user to the https version.
If a website does not use https, you must never enter your personal information.
Install a reliable anti-virus that can root out malware. It can potentially monitor web browser cookies and deliver them to the attacker without your notice. It will also warn you if you try to open malicious links.
Public Wi-Fi hotspots are vulnerable networks due to weak security. This security can be exploited by an attacker to carry out Man-in-the-Middle attacks by posing as a trusted access point. FastestVPN utilizes AES 256-bit encryption to secure communication. It is military-grade encryption that’s near-impossible to crack, thus allowing you to send data over the internet without the fear of theft.
In addition to strong encryption, FastestVPN also features Anti-Malware Protection and Ad-Blocker. Anti-Malware Protection crosschecks websites against malicious websites and blocks them from returning.
Lastly, always be vigilant about clicking on unknown links, they are often phishing attempts to steal information. And always use encryption when communicating sensitive information online.