How Are Viruses Sent Over The Internet?

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Security Tip - Be Careful with Attachments:
Well, it's been another big year for hackers. There have been a number of  really bad viruses just within the past 6 months. We've seen the  W32.Beagle, W32.Netsky, MyDoom, and so on and so on. Most of these viruses  were transported or replicated from pc to pc using email attachments.  These are easy to spot if you're paying attention, simply because they are  usually executable files, but not always.
 
Some attachments contain Macros (simple programs that run within other  programs-all the titles in Microsoft Office use macros). If you're not  that familiar with spotting file extensions, don't worry, that's what I'm  here to talk about today. If your a little hazy on the whole "file  extension" thing then let's spend a few moments explaining it.
 
File extensions are what tell the program how to treat a particular piece  of data. For example, most people are somewhat familiar with .doc or a  .txt file extensions these are both text documents and when the user opens  this file the Operating System looks at this extension and then knows how to open it.
 
Hackers try to use some sort of eye-grabbing ploy to get you to open their  email and activate the virus which is always an attachment. Most  Anti-virus nowadays stop, or at least warn, you of these high risk  attachments and even take measures to protect you. However, on the average  10-15 new viruses are created every day and I personally wouldn't count on  any program to 100% protect my pc. That's why I scrutinize any email-if I wasn't expecting an attachment, I won't open it until I had a chance to  talk to the sender.

.scr - Windows Screen Saver - USE CAUTION if you receive a screen saver
via email. They can contain worms or viruses
.pif - DO NOT OPEN! This is most likely a virus. Clicking it will run a
program or code that can mess up your computer.
.exe - executable file - a program that can contain a virus, trojan horse, or
worm (except for e-books from "EmuOilDepot.Com!")
.pps - MS PowerPoint (can contain macro virus)
.zip - Zip (compressed) file
.vbs - Visual Basic script
.bat - Executable MS-DOS batch file
.com - DOS executable command
.asp - active server page - internet script
.doc - Word document (can contain macro virus)
.xls - Excel file (can contain macro virus)

This is in no way a complete list. Just because an attachment may have one of these extensions doesn't mean that it is a virus, but it should send up warning flags. Hackers use clever subject lines, and viruses can appear to come from a friend so keep on your toes and don't fall victim to their deceptive traps. Scan those attachments and verify with the sender before opening.

Stay safe out there,
Chad