How to hack online Sessions : Session Hijacking

How Session Hijacking works

What is Session Hijacking?
Let's discuss them in common term's, Session Hijacking by the name only it suggests that we are hacking someone's active session and trying to exploit it by taking the unauthorized access over their computer system or Network. So Session Hijacking is the exploitation of valid computer or network session. Sometimes technical guys also call this HTTP cookie theft or more correctly Magic Cookie Hack. Now you guys surely be thinking what is Magic Cookie.
Magic cookie is simply a cookie that is used to authenticate the user on remote server or simply computer. In general, cookies are used to maintain the sessions on the websites and store the remote address of the website. So in Session Hijacking what Hacker does is that he tries to steal the Magic cookies of the active session that's why its called HTTP cookie Theft. Nowadays several websites has started using HTTPS cookies simply called encrypted cookies. But we all know If encrypter exits so its decrypter also

Session Hijacking is the process of taking over a existing active session. One of the main reason for Hijacking the session is to bypass the authentication process and gain the access to the machine. Since the session is already active so there is no need of re-authenticating and the hacker can easily access the resources and sensitive information like passwords, bank details and much more. 

Different Types of Session Hijacking

Session Hijacking involves two types of attacks :
1. Active attack
2. Passive attack


In Passive attack, the hacker Hijacks a session, but just sits back and watches and records all the traffic that is being sent from the computer or received by the computer. This is useful for finding the sensitive information like username passwords of websites, windows and much more...


In Active attack, hacker finds the active session and takes over it. This is done by forcing one of the parties offline which is usually achieved by DDOS attack (Distributed Denial of service attack) . Now the hacker takes control over the active session and executes the commands on the system that either give him the sensitive information such as passwords or allow him to login at later time.
 There are also some hybrid attacks, where the attacker watches a session for while and then becomes active by taking it over. Another way is to watch the session and periodically inject data into the active session without actually taking it over.

Methods to Hijack Sessions 
There are four main methods used to perpetrate a session hijack. These are:

• Session fixation, where the attacker sets a user's session id to one known to him, for example by sending the user an email with a link that contains a particular session id. The attacker now only has to wait until the user logs in.
• Session sidejacking, where the attacker uses packet sniffing to read network traffic between two parties to steal the session cookie. Many web sites use SSL encryption for login pages to prevent attackers from seeing the password, but do not use encryption for the rest of the site once authenticated. This allows attackers that can read the network traffic to intercept all the data that is submitted to the server or web pages viewed by the client. Since this data includes the session cookie, it allows him to impersonate the victim, even if the password itself is not compromised. Unsecured Wi-Fi hotspots are particularly vulnerable, as anyone sharing the network will generally be able to read most of the web traffic between other nodes and the access point.
• Alternatively, an attacker with physical access can simply attempt to steal the session key by, for example, obtaining the file or memory contents of the appropriate part of either the user's computer or the server.
• Cross-site scripting, where the attacker tricks the user's computer into running code which is treated as trustworthy because it appears to belong to the server, allowing the attacker to obtain a copy of the cookie or perform other operations.

TCP/IP & UDP Attacks Introduction

Hello, Lets explain "TCP/IP & UDP Attacks", Most common and effective Web attacks...Lets Know about its basic and types...

TCP/IP Attacks
1. TCP SYN or TCP ACK Flood Attack
2. TCP Sequence Number Attack
3. TCP/IP

TCP operates using synchronized connections. The synchronization is vulnerable to attack; this is probably the most common attack used today. The synchronization or handshake, process initiates a TCP connection. This handshake is particularly vulnerable to a DoS attack referred to as the TCP SYN Flood attack. The process is also susceptible to access and modification attacks, which are briefly explained in the following sections.

TCP SYN or TCP ACK Flood Attack - This attack is very common... The purpose of this attack is to deny service. The attack begins as a normal TCP connection: the client and the server exchange information in TCP packets. The TCP client continues to send ACK packets to the server, these ACK packets tells the server that a connection is requested. The server thus responds to the client with a ACK packet, the client is supposed to respond with another packet accepting the connection to establish the session. In this attack the client continually send and receives the ACK packets but it does not open the session. The server holds these sessions open, awaiting the final packet in the sequence. This cause the server to fill up the available connections and denies any requesting clients access.

TCP Sequence Number Attack - This is when the attacker takes control of one end of a TCP session. The goal of this attack is to kick the attacked end of the network
for the duration of the session. Only then will the attack be successful. Each time a TCP message is sent the client or the server generates a sequence number. The attacker intercepts and then responds with a sequence number similar to the one used in the original session. This attack can then hijack or disrupt a session. If a valid sequence number is guessed the attacker can place himself between the client and the server. The attacker gains the connection and the data from the legitimate system. The only defense of such an attack is to know that its occurring... There is little that can be done...

TCP Hijacking - This is also called active sniffing, it involves the attacker gaining access to a host in the network and logically disconnecting it from the network. The attacker then inserts another machine with the same IP address. This happens quickly and gives the attacker access to the session and to all the information on the original system.

UDP attacks

1. ICMP Attacks
2. Smurf Attacks
3. ICMP Tunneling

UDP packets aren't connection oriented and don't require the synchronization process as with TCP. UDP packets, however, are susceptible to interception, thus it can be attacked. UDP, like TCP, doesn't check the validity of an IP address. The nature of this layer is to trust the layer above it (I'm referring to the IP layer). The most common UDP attacks involve UDP flooding. UDP flooding overloads services, networks, and servers. Large streams of UDP packets are focused at a target, causing UDP services on that host to shut down. It can also overload the network and cause a DoS situation to occur.

ICMP Attacks - This occur by triggering a response from the ICMP protocol when it responds to a seemingly legitimate request (think of it as echoing). Ping for instance, that uses the ICMP protocol. sPing is a good example of this type of attack, it overloads te server with more bytes than it can handle, larger connections. Its ping flood.

Smurf Attacks - This attack uses IP spoofing and broadcasting to send a ping to a group of hosts on a network. When a host is pinged it send back ICMP message traffic information indicating status to the originator. If a broadcast is sent to network, all hosts will answer back to the ping. The result is an overload of network and the target system. The only way to prevent this attack is to prohibit ICMP traffic on the router.

ICMP Tunneling - ICMP can contain data about timing and routes. A packet can be used to hold information that is different from the intended information. This allows an ICMP packet to be used as a communications channel between two systems. The channel can be used to send a Trojan horse or other malicious packet. The counter measure is to deny ICMP traffic on your network.

Warning : ICMP can be very dangerous..and Even, as i said ...Don't try such attack from your pc, untill you don't know that how to be invisible on net ! Beccause once you get traced out ...No one can help you from Troubles..