Appendix B. The file extensions list

Once these extensions were generated, I examined all 169 455 combinations through Windows Explorer, in order to determine the system behavior towards these files. The biggest majority of these files turned out to be generic file extensions, meaning that no application is associated with them, and as such represents no harm in the aspect of this research. So I proceeded to extract all file extensions that Windows knew something about, by examining the file icon and file description. Some of these extensions are native to the Windows operating system, some others are the result of application softwares installed on my machine. For this reason, we can't qualify this list as "the ultimate file extension list under Windows", since a system configured for different needs would have produced a different list. However, the list presented here is somewhat complete and is a good reference material. Some application softwares also identify some file extensions with the application name, instead of the more generic extension name (for example, .wav is labeled WinAmp media file). I did not take the time to correct these entries, but I have received some corrections from JFC and Seva Gluschenko, so I have updated the list accordingly, along with remarks about the presence of NeverShowExt or if the files are considered to be executable (question mark ? means possible executable file, but not tested). Executable means it is covered by one of the four types of executability discussed in chapter 5.

This list is provided as is, and is only a by-product of my original research. There could be mistakes or ommissions, if this is the case, simply notify me and I will update the list accordingly. You can always check out the website for a more complete list.

.323 H.323 Internet Telephony
.386 Virtual Device Driver - Executable

.669 WinAmp media file

.aca MS Agent Character file
.acf MS Agent Character file
.acg MS Agent Preview file
.acs MS Agent Character file
.ade MS Access Project Extension - Executable
.adn MS Access Blank Project Template - Executable
.adp MS Access Project - Executable
.aif Mac .aiff Sound Clip
.ani Animated Cursor
.arc PkArc DOS archive
.arj ARJ archive
.art ART image
.asa Active Server Document
.asf Streaming Audio/Video File
.asp Active Server Document - Executable
.asx Streaming Audio/Video shortcut - Executable
.au  AU Format Sound
.avi Video clip
.awd Fax Viewer Document

.b64 base64-encoded file
.bas Visual Basic Class Module - Executable
.bat MD-DOS Batch file - Executable
.bhx Mac BinHex-encoded file
.bmp Bitmap Image

.c   C source code
.cab Windows propietary archiver
.cat Security Catalog
.cda WinAmo media file
.cdf Channel File
.cdx Active Server Document
.cer Security Certificate
.chm Compiled HTML Help file - Executable
.cil Clip Gallery Download Package
.cmd Windows NT Command Script - Executable
.cnf SpeedDial (NeverShowExt) - Executable
.com MS-DOS Application - Executable
.cpl Control Panel extension - Executable
.crl Certificate Revocation List
.crt Security Certificate
.css Cascading Style Sheet Document - Executable
.csv MS Excel Comma Separated Values file
.cur Cursor

.dcx DCX Image Document
.der Security Certificate
.dic Text Document
.dif MS Excel Data Interchange Format
.dll Application Extension - Executable
.doc MS Word Document
.dot MS Word Template
.dqy MS Excel ODBC Query file
.drv Device Driver
.dsm WinAmp media file
.dsn MS OLE DB Provider for ODBC Drivers
.dun Dial-Up Networking Exported file
.drv Device Driver - Executable

.eml Outlook Express Mail Message
.exc Text Document
.exe Application - Executable, by definition

.far WinAmp media file
.fav Outlook Bar Shortcuts
.fdf Adobe Acrobat Forms Document
.fnd Saved Search
.fon Font file

.gfi GFI File
.gfx GFX File
.gif GIF Image
.gim GIM File
.gix GIX File
.gna GNA File
.gnx GNX File
.gra MS Graph 2000 Chart
.grp MS Program Group
.gwx GWX File
.gwz GWZ File
.gz  GNU zip

.h   C definition code
.hlp Help File - Executable
.hqx Mac archiver file
.ht  HyperTerminal file
.hta HTML Application - Executable
.htm MS HTML Document 5.0 - Executable
.html MS HTML Document 5.0 - Executable
.htt HyperText Template
.htx Internet Database Connector HTML Template

.icc ICC Profile
.icm ICC Profile
.ics iCalendar File
.idf MIDI Instrument Definition
.iii Intel IPhone Compatible
.inf Setup information - Executable
.ini Configuration Settings
.ins Internet Communication Settings - Executable
.iqy MS Excel Web Query File
.isp Internet Communication Setting - Executable
.it  WinAmp media file
.its Internet Document Set
.ivf IVF File

.job Task Scheduler Task Object
.jod MS.Jet.OLEDB.4.0
.jpe JPEG Image
.jpg JPEG Image
.js  JScript file - Executable
.jse Jscript Encoded Script File Ink Shortcut - Executable

.lnk Shortcut (NeverShowExt) - Executable
.lsf Streaming Audio/Video file
.lsx Streaming Audio/Video shortcut
.lwv MS Linguistically Enhanced Sound File
.lzh LZH DOS archiver

.m1v Movie Clip
.m3u WinAmp Playlist file
.mad MS Access Module Shortcut (NeverShowExt) - Executable?
.maf MS Access Form Shortcut (NeverShowExt) - Executable?
.mag MS Access Diagram Shortcut (NeverShowExt) - Executable?
.mam MS Access Macro Shortcut (NeverShowExt) - Executable?
.maq MS Access Query Shortcut (NeverShowExt) - Executable?
.mar MS Access Report Shortcut (NeverShowExt) - Executable?
.mas MS Access StoredProcedure shortcut (NeverShowExt) - Executable?
.mat MS Access Table Shortcut (NeverShowExt) - Executable?
.mav MS Access View Shortcut (NeverShowExt) - Executable?
.maw MS Access Data Access Page Shortcut (NeverShowExt) - Executable?
.mda MS Access Add-in
.mdb MS Access Database - Executable
.mde MS Access MDE Database - Executable
.mdn MS Access Blank Database Template
.mdt MS Access Add-in data
.mdw MS Access Workgroup Information
.mdz MS Access Database Wizard Template
.mht MS MHTML Document Document 5.0
.mid MIDI file
.mim WinZip file
.mmc Medias Catalog
.mod MODplayer Media file
.mov Quicktime movie clip
.mp1 MPEG1-audio file
.mp2 MPEG2-audio file
.mp3 MPEG3-audio file
.mpa MPEG Movie Clip
.mpe MPEG Movie Clip
.mpg MPEG Movie Clip
.msc MS Common Console Document - Executable
.msg Outlook Item
.msi Windows Installer Package - Executable
.msp Windows Installer Patch - Executable
.mst Visual Test Source Files - Executable
.mtm WinAmp Media file

.nsc NSC File (have an icon, probably associated with Media Player)
.nws Outlook Express News Message

.oft Outlook Item Template
.opx MS Organization Chart 2.0
.oqy MS Excal OLAP Query File
.oss Office Search

.p10 Certificate Request
.p12 Personnal Information Exchange
.p7b PKCS #7 Certificates
.p7m PKCS #7 MIME Message
.p7r Certificate Request Response
.p7s PKCS #7 Signature
.pcd Photo CD Image - Executable
.pcx PCX Image Document
.pdf Adobe Acrobat Document
.pfx Personnal Information Exchange
.pgd PGPDisk volume
.pif Shortcut to MS-DOS Program (NeverShowExt) - Executable
.pko Public Key Security Object
.pl  Perl file - Executable
.pls Winamp Playlist file
.png PNG Image
.pot MS PowerPoint Template
.ppa MS PowerPoint Addin
.pps MS PowerPoint Slide Show
.ppt MS PowerPoint Presentation
.prf PICSRules File
.ps  PostScript file - Executable
.pwz MS PowerPoint Wizard
.py  Python file - Executable

.qcp QUALCOMM PureVoice File
.qt  QuickTime Video Clip
.que Task Scheduler Queue Object

.rat Rating System File
.reg Registration Entries - Executable
.rmf Adobe Webbuy Plugin
.rmi MIDI Sequence
.rqy MS Excel OLE DB Query files
.rtf Rich Text Format

.s3m ScreamTracker3 Media file
.scf Windows Explorer Command (NeverShowExt, generic icon) - Executable?
.scp Dial-Up Networking Script
.scr Screen Saver File - Executable
.sct Windows Script Component - Executable
.shb Shortcut into a document (NeverShowExt) - Executable
.shf PGP Share
.shs Shell Scrap object (NeverShowExt) - Executable
.sig PGP Detached signature file
.skr PGP Private Keyring
.slk MS Excel SLK Data Import Format
.snd AU Format Sound
.snp Snapshot File
.spa Flash Movie
.spc PKCS #7 Certificates
.spl Shockwave Flash Object
.sst Certificate Store
.sta sta file (Eudora)
.stl Certificate Trust List
.stm WinAmp media file
.swf Shockwave Flash Object
.swt Generator Template
.sys System file

.tar TAR archive file
.taz gzipped TAR archive
.tgz gzipped TAR archive
.tif TIFF Image Document
.ttf TrueType Font file
.txt Text Document
.tz  gzipped TAR archive

.udl MS Data Link
.uls Internet Location Service (generic icon) - Executable?
.ult Winamp media file
.url Internet Shortcut (NeverShowExt) - Executable
.uu  UUencoded file
.uue UUencoded file

.vb  VBScript File - Executable
.vbe VBScript Encoded Script File - Executable
.vbs VBScript Script File - Executable
.vcf vCard File
.vcs vCalendar File
.voc Winamp Medias file
.vsd VISIO 5 drawing
.vss VISIO 5 drawing
.vst VISIO 5 drawing
.vsw VISIO 5 drawing
.vxd Virtual device driver - Executable

.wab Address Book File
.wav Waveform audio file
.wbk MS Word Backup Document
.wht MS NetMeeting Whiteboard Document
.wif WIF Image Document
.wiz MS Word Wizard - Executable
.wlg Dr. Watson Log
.wm  Windows Media Audio/Video File
.wma Windows media audio
.wpd WordPerfect file
.wpz Winamp extension installation file
.wri Write Document
.wsc Windows Script Component - Executable
.wsh Windows Script File - Executable
.wsh Windows Scripting Host Settings File - Executable
.wsz Winamp extension installation file

.xif XIF Image Document
.xla MS Excel Add-in
.xlb MS Excel Worksheet
.xlc MS Excel Chart
.xld MS Excel 5.0 DialogSheet
.xlk MS Excel Backup File
.xll MS Excel XLL
.xlm MS Excel 4.0 Macro
.xls MS Excel Worksheet
.xlt MS Excel Template
.xlv MS Excel VBA Module
.xlw MS Excel Workspace
.xm  ScreamTracker media file
.xml XML Document
.xnk Exchange Shortcut (NeverShowExt) - Executable?
.xsl XSL Stylesheet
.xxe XXencoded file

.z   Compressed file
.z0  Z0 file (ZoneAlarm)
.z1  Z1 file (ZoneAlarm)
.zip Zipped file
.ZL?  ZoneAlarm Mailsafe Renamed File

ZoneAlarm Mailsafe will quarantine mail attachments and changes
their extension. The conversions are:

.ADE to .ZL0
.ADP to .ZL1
.BAS to .ZL2
.BAT to .ZL3
.CHM to .ZL4
.CMD to .ZL5
.COM to .ZL6
.CPL to .ZL7
.CRT to .ZL8
.EXE to .ZL9
.HLP to .ZLA
.HTA to .ZLB
.INF to .ZLC
.INS to .ZLD
.ISP to .ZLE
.JS to Z0
.JSE to .ZLF
.LNK to .ZLG
.MDB to .ZLH
.MDE to .ZLI
.MSC to .ZLJ
.MSI to .ZLK
.MSP to .ZLL
.MST to .ZLM
.PCD to .ZLN
.PIF to .ZLO
.REG to .ZLP
.SCR to .ZLQ
.SCT to .ZLR
.SHS to .ZLS
.URL to .ZLT
.VB to .Z1
.VBE to .ZLU
.VBS to .ZLV
.WSC to .ZLW
.WSF to .ZLX
.WSH to .ZLY

Appendix A. The Perl script

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