All posts by Ramesh Jha

how to protect against internet threats

secure yourself by making strong password

Increasing internet threats are becoming a big headache thesedays.Hence it seems very difficult to protect against internet threats during online activities.But with few basic precautions it is very easy to secure yourself fr0m most of the crackers and script kiddies;most of the crackers and script kiddies succeeded due to the ignorancy of the end user.Most people think that installing a good antivirus or a firewall or antispyware implies that I am hundred percent secure fr0m any internet threats OR some people don’t like to use any antivirus software as they feel that my computer become too slow OR some even don’t know that the cracker or script kiddies can harm up to such large extent.The username and password combination is most widely used authentication system but here is the common problem in choosing the password.
(1)most user like to use simple password such as 12345 or asdfg or.. so that they can remember easily;
But it can be hacked very esily using simple dictionary attacks.

(2)they want to use some familiar number or string such as name,cell,Date Of Birth or phone number,other card numbers.
But it can br easily guessed by some one who know about that user or these simple infr0mation can be easily obtained by doing some simple research(e.g by using social networking site like facebook,orkut,myspace or microblogging site like twitter).

Here is the simple tips so that you can protect yourself against the internet threats and feel safer –

#1.How to Make your password strong : Hard to crack


Make the password strong by combining :
1.upper and lowercase characters.
2.numbers
3.special symbols
e.g Ap8@V&R50#Wx
If you feel difficulties in the case when you have to maintain more than one password then remember one and add some extra character in front,last or middle to distinguished fr0m other password(recommended method)
e.g for account1 : Ap8@V&R50#WxZ1
for account2 : Ap8@V&R50#WxZ2 strong one OR apply some more concept and make your password stronger e.g : Bq9@V&R50#WxZ2 (*Hint : I have shifted one to the right in the digits coming before the first ‘@’ symbol and the remaining part is same only).
Alternative Method : Store the password in file(so that you will have to remember only a master password)and encrypt it using software like true crypt or GNU Privacy Guard.Both of these softwares are open source,free and available for all major platfr0m(Linux,Windows and Mac OS).
Downloading link :  Truecrypt GNU PG

#2.Precautions for those who use public computers/cyber cafe:

1. Don’t do online banking or purchasing works if it is so necessary then use on-screen keyboard(go to the start menu and search for that it should be installed by default).
[Because it will secure you fr0m the key loggers programs]

2. Always logout fr0m your logged in accounts e.g fr0m social networking websites like orkut or facebook before leaving the computer.
[because others may misuse your account for any purpose]

3. After using the cafe change your password as soon as possible.
[If the administrator is sniffing the traffic then he may get your password and other sensitive inf0rmation easily if  the connection is not encrypted]

4. Do not save the password at the time of logging. when firefox or other browser says “save the password” always click no OR simply go to the preference tab and change the setting such that it won’t offer to remember any password for the sites.(In firefox just uncheck the box that offer to remember the passwords).
[Otherwise anyone can easily view your password by clicking on show the saved password if the master password is not installed]

#3 Common precautions for all users :


1. Password recovery options are sometimes ignored by the users but it is an important point to note that the security question(s) in gmail/yahoo or other websites are as important as password.So make your security question harder to guess and associates the email accounts with each other so that one can be recovered fr0m other in case of any problem.

2.Use your credit card with trusted sites only and in case of secure connection you will see :
*The web address start with https instead of http
*A lock symbol appear near the right bottom corner(firefox).
*You can see the certificates information by right clicking and select “view certificates” to know more about the ssl provider and encryption level(It should be more than 128 bit).

3.Use good antivirus software like Avast antivirus(It is available free for home users) and always scan the external memory devices before transferring any data to your computer.You can shedule the scanning according to your need or choice. Download avast (Windows users) {It is optional for LINUX users as linux is almost Virus FREE although there are many open source virus scanners are available like clamtk: Download clamtk virus scanner}

4.For online banking or any other account ..always open their websites by typing their address in the address bar.It will prevent you fr0m the most common attack known as phishing attack in which you will submit your login information through a fake website(Although it looks similar to the original but the URl is different..or just similar hence see the URL carefully) and your information will be parsed somewhere else using some script languages like PHP,JAVASCRIPT.

5. Use good firewall to protect your computer fr0m the common online attacks and try to learn about the policy so that you can tune their settings according to your need and the security level you want.

how to manage e-books collection/library

Now e-books are becoming more popular and useful.When you have a number of e-books on different categories then it is difficult to keep track of  them.That’s why you need a library manager so that you can manage your collections more effectively.I am going to introduce you with an open source software which is a complete solution to the e-book library management.

CALIBRE : An open source and cross platform e-book library manager which can be used to view,catalog and convert e-books in all the common available formats of e-book ,e.g pdf,LRS,txt.It can also convert the simple format information into e-books to make the reading easier.

supported input – e-book formats are :
MOBI , LIT , PRC, EPUB, ODT, HTML, CBR, CBZ, RTF, TXT, PDF, LRS.

Supported Opeating systems are :
Linux, Wndows, OS X

Download calibre

new features of ubuntu 10.04

Mozilla firefox : ubuntu 10.04 beta came with the latest verson of mozilla firefox 3.6 ,and the default search engine is yahoo.

Desktop : ubuntu 10.04 beta lts came with the latest verson of GNOME desktop(as default) with some new features and programs.

Linux-cernel : it has come with 2.6.32-16.25 kernel.

Hal removal : the ubuntu 10.04 came with the support of full removal of hal fr0m the booting steps,hence the boot process will become more faster and it will become easy to resume in the case of suspend.

New charming themes : Two new themes ambiance and radiance has added along with some new wallpapers and icons.

New indicators : Some indicators has added to make the notification process  more consistent and well designed & optimised for session management works,communication and other tasks.

The final stable version will be released on April 29 2010.

You may like these posts :

How To Learn Ubuntu-Linux Commands

How to hack websites easily

how to hijack a tcp connection|hacking tcp sessions

credit : www.ubuntu.com

how to hijack a tcp connection|hacking tcp sessions

Hijacking a tcp connection requires just a little bit knowledge about IP spoofing and ACK numbers. IP spoofing is a simple technique in which the attacker/hacker replaces the IP address of the sender i.e sends some data by confusing the receiver.ACK or SEQ numbers are used by the web servers to distinguished between different sessions and to check that whether the user’s session is still active or not.In fact hijacking a tcp connection is not a difficult task;here is the simple description so that you can understand the basic steps.

So the tcp connection-session can be hijacked in the following simple steps –

step1 : Try to learn more and more about that victim-Z and the web server-F before proceeding to the next step.If you are monitoring the connection in a wireless network then you can also use wire-shark or other advanced network traffic monitor tools.(You can also use a Linux based operating system “Linux-back track-4” specially designed for hackers and penetration testing,because it contains all the required tools by default.)


step2 : The web server-F sends an echo back to the victim-Z and the victim acknowledges the data packet.


step3 : Now you can send the spoofed packet to the web server-F.


Step4 : Then the web server-F responds to you and you can start verifying ACK/SEQ numbers and the web server believes that the session is going on with the victim-Z.Now you have hijacked the session of the victim-Z.


Step5 : So you can continue the use of that session and web server will returned the requested information by checking the ACK number..and the connection will be continue until the FIN flag is changed to terminate.

what is ip fragment attacks|IP fragmentation hacks

IP Fragment

IP fragments is useful in keeping tracks of the different parts of a datagram in TCP/IP suite.When the data packets arrived at the destination field then it is used to reassemble the datagrams.The identification value of all the IP fragments are same so the fragmentation offset is used to indicates the actual position of the current fragment in actual datagram packet.

Hacking/attacking IP fragments

In general the ip fragments do not coincides but a hacker can create ip fragments packets artificially,in order to forge the firewalls or routers.Suppose the second fragment of the datagram packet is inserted to the sequence by the hacker and the offset value of the second packet is less than the length of the first fragment.Then this situation may results in the overriding some bytes of the first segment on the time of reassembly at end computer.So this defected ip fragments may be responsible for the improper functioning (or crash) of the operating system.This is known as ip fragment attacks.A simple example of the ip fragmentation attack is the ping of death attack which sends the ip fragments that create the larger packets then the maximum allowed length at end computer.