Some types of files are more dangerous to download than others. The first step to protecting yourself from dangerous files is learning to recognise what it is you are actually downloading. The name and file extension can tell you a lot about a file.

File types to treat with CAUTION

These are the file types with the most potential to change and effect your computer. You may well have a legitimate need to download any of these file types, but always consider where you downloaded it from.

Programs Scripts & Others Archives (zipped folders) Office Macros
Always download programs from the original vendor A script is a file containing commands that can change your computer settings Compressed folders like .zip may contain any manner of files. Office files that contain additional code scripted by the author
.exe
.msiLess common:
.application
.gadget
.scr
.hta
.cpl
.msc
.jar		 .bat
.cmd
.vb
.vbs
.js
.jse
.ws
.wsh
.reg
.scf
.LNK
.inf		 .zip
.cbr
.cb7		 .DOCM
.DOTM
.XLSM
.XLTM
.XLAM
.PPTM
.POTM
.PPAM
.PPSM
.SLDM

Other common file extensions:

Get to know these common file types so you understand what you are actually downloading. General safer, same of these formats can still contain malicious code.

Picture Audio Video Documents Microsoft Office
.jpg
.jpeg
.gif
.png
.tif
.tiff		 .mp3
.wav
.AIFF		 .avi,
.mpg,
.mpeg,
.wmv,
.mov		 .txt
.pdf
.html
.rtf
.epub
.pdb
.mobi		 .doc – Word document,
.docx – Word document,
.pps – Powerpoint,
.ppsx – Powerpoint,
.xls – Excel Spreadsheet,
.xlsx – Excel Spreadsheet