What was the first thing that attracted you when you were introduced to Internet?
Instant Messaging comes to our mind instantly, doesn’t it? But how many of us realize that this addictive feature of the Internet is indeed the gate opener for many an intruder? Many internet users have inseparable relationship with popular IMs like Yahoo messenger and MSN messenger.
Large number of employees in most small and big corporations uses instant messengers almost on a daily basis, for both business purposes and personal relationships. However, despite their numerous advantages, instant messengers open up yet another route (and the easiest one that is) through which the privacy of users can be violated. An attacker can easily use these IM systems to find out the IP address of a remote system, which is the first step of “hacking”.
Depending upon the IM system that is being used, there are different ways to find the IP address.
How to find IP address?
Start a simple file transfer; go to the command prompt and then type the command “netstat –n” in your command prompt. Knowing the IP address, the intruder will find out which ports are open in the remote live system.
Ex:
1. If a ftp port is open one can install “keylogger”, which is a program that transfers every key typed by the victim including passwords!
2. If port 21554 is open, one can install a tremendously dangerous Trojan called “girl friend” which damages your system irrevocably. If 8897 is open, one can access your drives sitting at one’s computer.
3. Also, by knowing the IP address, the intruder can perform DOS (Denial Of Service) attacks on your computer. For example, if yours is a UNIX system, the attacker can perform “Ping Of Death” which incurs complete damage to the system. A system can take a maximum of 65535 packets at any moment of time. So if I type “ping 65540”, the system cannot take it.
A real case study is in France an attacker gained access to a reputed designers system and accessed all the designs that the latter’s company is planning to launch the next month, another company came out with same designs that the designers company planned to release a few days prior to the launch plan of the designers company . This resulted in heavy loss and the designers toil is in gutter.
So how are we going to fight them?
Here are some counter measures:
1. It is best to avoid file transfers, voice conversations , web cam conversations with strangers
2. The best always to use a proxy server. It acts as a buffer between you and the untrusted internet. Almost all IMs allow to use proxy servers.
Ex: On MSN messenger,
A. Click on tools>options
B. Click on CONNECTION tab.
C. Enable the “I use a proxy server” option
D. Enter the details of your proxy server in the space provided below and click the ok button.
3. Remember, a webcam chat opens more ports on your system which enables the attacker to install Trojans on your system.
Author: Sneha, Vizag (Andhra Pradesh)
