Executable file extensions

Invisible Files

Some file extensions are by default suppresed from displaying in Windows Explorer and other programs. This allows virus writers and malicous code to distribute executable files disguised as something non-executable. For example, a *.exe file might appear to be a text file.

Executable File Extensions

The following is a list of file types that should be considered suspicious when received as attachment in mails. These files should not be opened unless you really know what they contain. Many viruses and malicious software distributes by sending its content as an attatchment with such an extension.

List of Extensions

Microsoft Access Project Extension	*.ADE
Microsoft Access Project	*.ADP
Visual Basic Class Module	*.BAS
Batch File	*.BAT
Compiled HTML Help File	*.CHM
Windows NT Command Script	*.CMD
MS-DOS Application	*.COM
Control Panel Extension	*.CPL
Security Certificate	*.CRT
Dynamic Link Library	*.DLL
Word Documents and Templates	*.DO*
Application	*.EXE
Windows Help File	*.HLP
HTML Applications	*.HTA
Setup Information File	*.INF
Internet Communication Settings	*.INS
Internet Communication Settings	*.ISP
JScript File	*.JS
JScript Encoded Script File	*.JSE
Shortcut	*.LNK
Microsoft Access Application	*.MDB
Microsoft Access MDE Database	*.MDE
Microsoft Common Console Document	*.MSC
Windows Installer Package	*.MSI
Windows Installer Patch	*.MSP
Visual Test Source File	*.MST
ActiveX Objects	*.OCX
Photo CD Image	*.PCD
Shortcut to MS-DOS Program	*.PIF
PowerPoint Templates	*.POT
PowerPoint Files	*.PPT
Registration Entries	*.REG
Screen Saver	*.SCR
Windows Script Component	*.SCT
Document Shortcut File	*.SHB
Shell Scrap Object	*.SHS
System Config/Driver	*.SYS
Internet Shortcut (Uniform Resource Locator)	*.URL
VBScript File	*.VB
VBScript Encoded Script File	*.VBE
VBScript Script File	*.VBS
Windows Script Component	*.WSC
Windows Script File	*.WSF
Windows Scripting Host Settings File	*.WSH
Excel Files and Templates	*.XL*