Protect your machine on a
Peer to Peer network
File extensions - Part 1
Warning: This information refers to Peer to Peer network downloads only. All file types have their legitimate uses, so if you're looking around your hard drive and find files that have been labelled below as dangerous, leave them alone, they're probably supposed to be there.
File extensions
For those who are unsure, the file extension is the bit after the dot at the end of the filename (e.g. Picture.jpg). It tells you the file’s format (in this case, JPEG), and can help you determine whether a download will be potentially problematic or not.
For this purpose, files can basically be broken down into the two groups of either: executable (which can contain a virus) or non-executable (which can’t), but as always, there are grey areas which are discussed in Part 2.
Unsafe executable file extensions common to every
Peer to Peer network. Filter out or simply ignore.
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Extension |
File type |
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.ade
.adp
.bas
.bat
.chm
.cmd
.com
.cpl
.crt
.dll
.exe
.hlp
.hta
.inf
.ins
.isp
.js
.jse
.lnk
.mdb
.mde
.msc
.msi
.msp
.mst
.ocx
.pcd
.pif
.pot
.ppp
.ppt
.reg
.scr
.sct
.shb
.shs
.sys
.url
.vb
.vbe
.vbs
.wsc
.wsf
.wsh
.xls
.xlm
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Microsoft Access Project
Microsoft Access Project
Visual Basic Class Module
Batch File
Compiled HTML Help File
Windows NT Command Script
MS-DOS Application
Control Panel Extension
Security Certificate
Dynamic Link Library
Application
Windows Help File
HTML Applications
Setup Information File
Internet Communication Settings
Internet Communication Settings
JScript
JScript Encoded Script
Shortcut
Microsoft Access Application
Microsoft Access MDE Database
Microsoft Common Console Document
Windows Installer Package
Windows Installer Patch
Visual Test Source
ActiveX Objects
Photo CD Image
Shortcut to MS-DOS Program
PowerPoint Templates
Peer to Peer network packet
MS PowerPoint
Registration Entries
Screen Saver
Windows Script Component
Document Shortcut
Shell Scrap Object
System Config/Driver
Internet Shortcut
VBScript
VBScript Encoded Script
VBScript
Windows Script Component
Windows Script
Windows Scripting Host Settings
Microsoft Excel Files and Templates
Excel Macro
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In fact, if you don’t recognize the file type as a standard image, video, audio, document, or archive file, don’t download it, and certainly don’t open it.
Safe executable file extensions common to every
Peer to Peer network.
| |
Extension |
File type |
|
| |
.ai
.art
.avi
.bmp
.cgm
.dat
.dvr-ms
.dwg
.dxf
.eps
.flv
.gif
.jpe
.jpg
.jpeg
.mid
.midi
.me
.mp2
.mp3
.mpg
.mpeg
.ogg
.pcx
.pdf
.png
.pps
.rle
.rm
.ram
.rtf
.tif
.tiff
.ttf
.txt
.vob
.wav
.wri |
Adobe Illustrator Image
Image
Video
Image
Image
Data
Video
Autocad Drawing file
Autocad Drawing file
Image
Flash Video
Image
Image
Image
Image
MIDI Audio
MIDI Audio
Text
Audio
Audio
Video
Video
Ogg Vorbis Audio
Image
Adobe Acrobat
Image
Powerpoint Presentation file
Image
Real Audio/Video
Real Audio/Video
RichText document
Image
Image
Font
Plaintext
DVD Video/Audio
Audio
Text |
|
Double extensions
Sometimes on a Peer to Peer network, you will see a file with what looks like two file extensions (e.g. Picture.jpg.exe). In truth, there’s still only one extension (.exe) but is being made to resemble an image (.jpg) file, and is without question something dangerous. Regardless of what you see in the filename, the designation after the last dot is the only one that counts when determining its type.
The problem with Windows is that its default setting hides the file extensions from the user, and means that if you downloaded the file ‘Picture.jpg.exe’ by mistake, it would appear on you machine as ‘Picture.jpg’. To prevent this from happening, you can change your settings to show the file extensions, as follows.
Note: You should only do this if you are an experienced computer user.
For Windows ME, 2000, or XP
- Click on start, then My Computer
- Select Tools from the menu, & click on Folder Options...
- Select the View tab
- In the Advanced settings: window, uncheck the box
labelled Hide extensions for known file types
- Click Apply, then OK
That’s it, you’re done. Care should be taken though, as it is now possible to alter the extension of a file in addition to its name, which may cause it to malfunction.
Now on to Part 2 of how to protect your machine while on a Peer to Peer network, and those grey areas mentioned earlier.
Become an expert downloader with the step-by-step tutorials and more in
'The Essential Guide to Downloading'
Peer to Peer network - File extensions (Top)
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