A simpler way to protect your usb stick from virus:

Time passes so fast or I Was so much busy I don't know .Its more than a year now since my last update on this blog!!

I had explained in my earlier post on how the file "autorun.inf" helps virus and worms in spreading themselves effectively.Recently I had come across an pretty interesting and simpler method of protecting your USB sticks from virus,this method is un-vulnerable upto certain extent(At least protection from ordinary class of virus).

The logic behind this is very simple. Just create a folder named "autorun.inf" in your root folder of the USB and assign only Read permissions to it ,that's it your USB stick is safe now.

So how does this protect my USB ??
The basic funda here is when you insert the USB onto any computer , the first thing virus tries to do is create an entry in the file autorun.inf or if the file doesn't exist it creates the file "autorun.inf" and make its entry over there.So when you have folder by that name(autorun.inf) in your root folder of your USB ,the viruses fails in its attempt to write in the file "autorun.inf" fails and hence the protection.

Earlier , my pendrive used to get corrupted with virus every time I used to get printouts from some cybercafes or printer shops. Now my pen-drive is safer ,its working quite well for me now a days.

Safer Way of Disk Unmounting

Thinking of some good topic to blog from many days, finally got one.

Many might have definitely faced this issue.You might have mounted cdrom/usb on linux box and after the work is done , when you try to umount it , you might see the linux box throwing the message /mnt/ is busy.

If you remove directly without doing unmounting , there will be a risk of getting bad sectors on the device.Another solution to halt(shutdown) the machine.(very odd option).Very few might be knowing of the linux command "fuser" which makes the life easy while unmounting.

If you encouter "/mnt/ busy " message while unmounting , just run the following command
$fuser /mnt/usb
>>which will show the pid of the process that is causing the unmount to fail.
Now just run
$fuser -k /mnt/usb ,
>>It will kill the process that is blocking the unmounting of the device.
Now do
$umount /dev/usb
Will be success now for sure

"fuser , my disk saver"

Verifying file integrity.

This post is all about the checksum, i have a read a lot about this topic in college days.Never had really hand experience how it can be used in daily life.

we download a lot of files from internet, copy files (movies ,songs .text and lot of other things) from friends place to our pen drive.Sometimes it may happen that , the file hasn't copied/downloaded properly :( .We realize this thing when we try to use the copied/downloaded content .
This is where our checksum comes into picture.Just to verify that the files are copied correctly Just use the "sum" Command in linux.
Just as an example:

Remote Host:
------------
$ sum vlc0.8.5test3win32.exe
20311 8132

After copying to pendrive or something.
---------------------------------------
[bash$pradeep@localhost]sum vlc0.8.5test3win32.exe
20311 8132

When you download a file , the checksum apart from verifying the file integrity helps us make sure that , the file we downloaded is not tampered by middle man.And it is virus free.

You can see many sites ,that provide some material to download has MD5/SHA1 signatures for the content they have kept for download.You can use this and verify that the piece of downloaded content is same as what is kept on the site and it is virus free.Sometimes it happens that , even though the content you downloaded works fine.But it is infected with virus.

This tool is very useful ("sum") to me in office .Very often i provide patches of our product to people .And provide them them the sum command output, to check whether the patch they had downloaded is fine. So that they wont come to me again saying , your patch is not proper . :)

All about autorun.inf

It is been long i thought of blogging about this topic, finally i am able to do this now.

What is this ?

I guess very few might have knowledge about this file, this is the file you most often see in the cd's(compact disc) home directory.You might have seen, when you insert cd into the drive , it gets auto started with some program,or it will open some default file , basically some sort of task is performed when cd is inserted.You might have wondered how this happened.Its all the magic of this autorun.inf file.

This is a some sort of script file ,which tells windows what to do upon the opening of folder in which it is located.which is type of initialization file ,which tells what actions to perform when the folder is opened.

We can do lot of things with it.You can make the windows set some background , when folder opens , and many more.This windows oses feature has made the viruses a way to spread themselves .Most often it is used by viruses ;).

Sometimes you might have seen , you try to open a drive/folder.It fails to
open.Its because of this autorun.inf.

How to locate and remove it ?
This file is always hidden in the folder.you can see this file in the root
folder of usb stick.You can use Dir /a to find that file from command line.Viruses make an entry in it , to run when the folder is opened.Just open that file from command line and see some malicious code has made an entry in it.If so you can safely delete this file.

Security flaw in delicious.

   I have a delicious account, i had kept auto login feature for it on my office computer.But when i tried to access my delicious account from my home desktop,then i realized that i had forgotten my password.So i thought of changing its password by going to link, i forgot my password, which will send the mail to my email account which i had registered while signing up.
   Its has been long time since i created my delicious account , the email id that i gave was too older one and i use it no more , hence i don't remember the password for it also!!!.Then i got perplexed how to change my password.just browsing through the delicious site, i went to settings of my account(from office computer where it is logged in already).I got shocked when i saw, i can change the email id which i used for registration without prompting for old password.I just changed that email id to my currently using email id.After that i went to forgot password link and gave my account id, which sent a mail to my current id from there i changed mypassword!!!
   It means if we login to our delicious account and left without logging off , then some one can easily change our password.!!!without knowing our old password,which can done by just changing the registered id.

How to browse the web in an efficient way

When i first got my internet connection at mysore, i was jubilant,browsed the web day and night ,after sometime i gone through the phase where exactly i didn't knew what to browse.Then i started thinking how to filter out of informative and interesting thing on the web.I got this idea after many days of browsing.

Each one browses web daily and ends some information in his kitty..To make a note of the all the vital things that he came across ,either he makes a bookmark locally or do it online on sites such as "Del.ic.ious","Google bookmarks".

If he gets some idea out of the things he browsed .He will write a blog entry.
If it is an important news , he diggs it in digg.com.

Your brain might already started thinking , how these all above things helps me to browse web effecient way.The answer to this is feeds and feedreader .We have now feeds available for all of the sites including the bookmarks,blogs and diggs of some one.All just i have to do is to "Subscribe to feeds" of the bookamarks,diggs and blogs of the person you know well in browsing in good things.From his network you can pick some other names.Just make the feed entries of all these things in your feedreaders -GoogleReader or other feed reader softwares.

By just going through the popular bookmarks on each of the famous bookmarking sites(delicious) or just subscribing for the feed, we get lot of useful and interesting information to digest.
Eg. Delicious http://del.icio.us/popular/
http://digg.com/all

At the end of day that's how i get some fruity stuff to browse.
This is what i follow to filter interesting and informative information on the web.
This is what i call lazy and effecient browsing ;)

Screen Saver - the screen life saver

Allmost all of them who use computer are well versed with the term "screen saver",butonly few might have tried to unearth its origin.what ever may be the case, let me explain laconic history about the origin of word "screen saver".

In earlier times when people used to keep the computer idle for long time, the contents of screen used to be same - same pixels form the screen contents.Implies the same set of electron beam strikes the screen for long duration,as a result monitor got damaged soon and its life got reduced.

Thats the point of time ,the smart people came into act ,found a new concept and coined it as "screen saver" . The "screen saver" continoulsy changes the contents of the screen(main logic), hence the pixels projected on the screen, preventing the damage of the screen and ameliorating the life of the monitor.Thus how the origin of the word "screen saver", came into existence.