This is something that EVERY internet computer user should know.
If you download, or open, or receive in any manor… and open… a file…
If it is an executable file, it CAN contain a virus.
If it is NOT an executable file, it CAN NOT contain a virus.
The easy way to be able to tell the difference, is to make yourself familiar with the file types that are safe.
You can tell by the LAST few letters… which appear AFTER the LAST dot (.)…. in the actual computer NAME of the file.
For example, a file called some_fun_vacation_pictures.jpg is a SAFE file.
On the other hand, a file called some_fun_vacation_pictures.jpg.scr is a very DANGEROUS file — probably a VIRUS.
Notice how –even though the name CONTAINS a .jpg — the LAST three letters… after the last dot (.)… are what count! And they are .scr
And .SCR is one of the file extensions that are DANGEROUS…
Because they are PROGRAMS… just like .exe AND .com They are not pictures or videos or text.
Get acquainted with, and refer often to, this list of Safe and Unsafe File Extensions.
To this list, I would add these:
Here are some more SAFE file extensions:
.jpg — a picture
.jpeg — a picture
.gif — a picture
.png — a picture
.tif — a picture
.tiff — a picture
.txt — a notepad text file
.doc — a word document file
.pps — a powerpoint presentation file
.pdf — an adobe acrobat readable document
.mp3 — music or audio
.wav — music or audio
.avi — a video
.mpg — a video
.mpeg — a video
.wmv — a video
.iso — a video (disc image file used to burn a copy of a DVD)
.flv — a video (flash video)
.mov — a video (apple quicktime video)
.dvr-ms — a video (tv program for windows media player)
.vob — encrypted video and audio files used on current DVD’s
WARNING — COMPRESSED FILE TYPES
There are also COMPRESSED file types. These compressed files Could be totally Safe… and they Could be Dangerous…
It all depends on WHAT FILES ARE CONTAINED INSIDE OF THEM… So make sure you look to see exactly what file types are contained INSIDE any compressed files…
Before you download them, and AGAIN,
Before you uncompress (or “extract”) them…
Compressed file types include:
.zip — a zip file (you can easily see what files are inside before you extract them… in windows just double-click the file)
.rar , .r00 , .r01 , etc. — RAR files (very similar to zip files. You will need WinRAR to uncompress / extract the files)
Also, although the following list does not tell you if the file extension is safe or not… it might give you some clue as to what type of file it is. See Every File Type in the World. If it says anything like “program”, or “executable”, or “code”, or anything that sounds like it could be a program… assume it is not safe. In fact, if you don’t immediately recognize the type as a standard picture, music, video, audio, or document file… just Don’t Download it, and Don’t Open it.
Basically, if it’s NOT on the SAFE list… Don’t Download it. Don’t Open it.