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PROTECT YOUR PC SECTION

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1. Generally easy support of windows shell script support and web scripting languages are one of the main cause of the virus attack from internet.
There are many ways for propagation of these viruses.

• When you visit any unknown website then that website may contain some links which automatically start downloading of some particular files. (Viruses/Adware/Trojan horse/Spyware etc). This task can be very easy if you have selected automatic download of essential software etc. (Look in your browser options). Apart from it, many website download some scripts(java/vb) to your computer, which do not contain virus information, so for all anti viruses, this script is normal one. But this script are executed in timely fashion, It automatically establish a connection to remote site(using ftp port) and then download the latest viruses for internet. Some viruses spread the virus from your system to others that make their chances less of being caught and can exponentially propagate. These viruses send emails to other computer and also send email to their developers. In the developer email all the information and important data related to your computer are stored such as data, passwords, account settings and many more, the viruses which do this task are sometime known as Spywares. Some virus come in form of advertisements(Adware). Generally adware cookies are famous now a days, these cookie keep tracking your area of interest and pass relative information to administrator.

Example: Many person got problem with automatic installation of Dialers. This Dialers silently got installed on you computer because either you have given permission to that dialers (See Internet Option: Automatic Downloads....) or you clicked a link that contain installation (may be that link does not really state what is behind it) e.g. GET MORE .. and when you click the link, it seems that you clicked on download and it automatically saves into your computer and installed at that moment. Really very easy task.

• There are some pictures which may contain virus codes when decoded. (Very popular now a days). After decoding it becomes the executable script and that drives installation.
• Automatic Pop up windows can contain download of the viruses by stating the wrong names like "Click on this free link to download" xyz utility which downloads utility +viruses. There are many cases in which some viruses try to attach themselves with executable codes and archives.
• Freely shared files which are available at free hosting services can contain virus codes.
• Dangerous: Many time some viruses when hit any computer. Then transfer their codes by capturing the proxy setting of the current network and throwing randomly to connected LAN/WAN and some time internet connection i.e. you have to log-in to internet to get the virus in your system! That truly depends upon security/firewall settings of your system.

There are many more ways.
2. Secondly, Spam Mails which includes unknown mail from your friends in address book. Have u seen the forwarded mail chain, if yes click on "Show Header" of the text the full header contains all the way from mail sent to the destination, their router servers and many more...
Spam mail can contain advertisement/viruses and many more. Some email providers have difficulty in detecting the spam. Main reason it according to the header information that mail is sent by your friends. e.g virus which contain Attachmentxyz.BHX files. Subject stating only Hi, Hello, Pics, Sexy and the similar ones, Don't open this file. First send a screenshot to your friend and tell him/her that whether you have sent this mails or not. If not delete these mail instantly. When you open the attachments or sometime msg(in HTML or RTF format) then automatically your computer will get infected. Because you have purposely opened the file. So Firewalls can not block it!!! Many odd looking images may be the virus codes when decrypted can do a disaster effects.
EXAMPLE:It seems that its quite difficult to send mail from unauthenticated account, then take a look at example:Check out how easy this to send a mail from one email Id to another without any authentication. In sending greetings we give only the email id's not the password. When receiver got the email then the To Field (sent by) field contain the email id of the person who sent that mail. That means if I know your email id then I can send greetings to anyone without your knowledge, this means easily anyone can send virus or spam. Quite easy job.
3. From Removable Media's, even fresh copy may contain signature of viruses so take care while using flash, removable harddisk and other data transfer devices. When we write a CD containing the virus code then that CD will copy the virus wherever it goes!!! It is very dangerous because you can't deleted the content(in Read Only case). If you find any, just break that CD. Virus are more likely to come from floppy and flash drives. Always check out the content before copying.

Continued HERE: PROTECT YOUR PC