Internet Security and Privacy - The File-Extensions List

Here we go... The "potentially dangerous" file list

Remarks:

In this list we use the file-extensions to lookup if a file could be dangerous or not. The file-extension is the code, including the period, following the file-name. You don't need to know much more about this to detect dangerous files, but if you have no more idea about file-names and extensions, it's a good idea to read something about it first (you can click below on the "related info"-button which brings you to the basic internet security page with more info this and other security threats).

In the list, the [*] symbol before each extension replaces the filename. The filename can be anything and has no importance, it's only the extension that matters here. After each extension, you can see what kind of file it belongs to (the file-type), but no need to remember that, just checking the extension will do.

All files with these extensions are potentially dangerous (this does not necessarily mean they contain a virus, but it's possible). Extensions with a "danger"-symbol added are very commonly used to spread a virus or other malware. Please remember, due to the continue changes in technology and the very large number of used extensions, a list like this will never be complete.

Remark: to download the list, including remarks, in a "printer-friendly" format, click the "print version" button at the bottom of this this page.

The "potentially dangerous" file list

*.ade	Microsoft Access Project-Extension	see remarks
*.adp	Microsoft Access Project	see remarks
*.app	Executable File (Program)
*.asf	Windows Media Audio/Video	see remarks
*.asp	Active Server Page
*.asx	Windows Media Audio/Video	see remarks
*.bas	Microsoft Visual Basic Class Module
*.bat	Batch File
*.cer	Internet Security Certificate
*.chm	Compiled HTML Help-File
*.cmd	Dos-CP/M-NT Command
*.com	Microsoft MS-DOS-Program
*.cpl	Control Panel Extension
*.crt	Security Certificate
*.csh	Csh-Code Script
*.dbx	Microsoft Visual Foxpro Table
*.der	DER-Coded X509 Certificate
*.doc	Microsoft Word Document	see remarks
*.exe	Windows Executable (Program)
*.fxp	Compiled Microsoft FoxPro Source Code
*.hlp	Windows Help-File
*.hta	Hypertext Program/Script
*.htm	HTML-Program/Script
*.html	HTML-Program/Script
*.inf	Setup-Information
*.ins	Windows Internet Naming Service
*.isp	Internet Communication Setup-File
*.its	Internet Document Set
*.js	JavaScript Source Code
*.jse	JavaScript Coded Scriptfile
*.key	Registry Entries
*.ksh	UNIX-ShellScript
*.lnk	Shortcut (Link)
*.mad	Shortcut to Microsoft Access-Module	see remarks
*.maf	Microsoft Access	see remarks
*.mag	Shortcut to Microsoft Access-Diagram	see remarks
*.mam	Shortcut to Microsoft Access-Macro	see remarks
*.maq	Shortcut to Microsoft Access-Query	see remarks
*.mar	Shortcut to Microsoft Access-Report	see remarks
*.mas	Saved Microsoft Access-Procedures	see remarks
*.mat	Shortcut to Microsoft Access-Table	see remarks
*.mau	Media Attachment Unit	see remarks
*.mav	Shortcut to Microsoft Access-View	see remarks
*.maw	Microsoft Access-Data Access-Page	see remarks
*.mda	Microsoft Access-Add-In	see remarks
*.mdb	Microsoft Access-Application	see remarks
*.mde	Microsoft Access-MDE-DataBase	see remarks
*.mdt	Microsoft Access-Add-On	see remarks
*.mdw	Microsoft Access-Workgroup Info	see remarks
*.mdz	Microsoft Access-Wizard Template	see remarks
*.mht	Web Archive File
*.mp3	Digital Audio (music file)	see remarks
*.msc	Microsoft Common Console Document
*.msh	Microsoft-Shell
*.msh1	Microsoft-Shell
*.msh1xml	Microsoft-Shell
*.msh2	Microsoft-Shell
*.msh2xml	Microsoft-Shell
*.mshxml	Microsoft-Shell
*.msi	Microsoft Windows Installer-Package
*.msp	Microsoft Windows Installer-Update
*.mst	Ms Win Installer/Ms Visual Test Source File
*.nch	Outlook Express Folder File