#
# NOTE: Fields are separated by TAB characters --- Important!
#
# Syntax is allow/deny/deny+delete, then regular expression, then log text,
#           then user report text.
#

# Due to a bug in Outlook Express, you can make the 2nd from last extension
# be what is used to run the file. So very long filenames must be denied,
# regardless of the final extension.
deny	.{150,}			Very long filename, possible OE attack						Very long filenames are good signs of attacks against Microsoft e-mail packages

# JKF 11/01/2006 Another Microsoft security vulnerability
deny	winmail\.dat$		Windows security vulnerability							No Outlook Rich Text Format messages due to security hole, use HTML instead

# JKF 01/01/2006 Another Microsoft security vulnerability
deny	\.wmf$			Windows Metafile security vulnerability						Possible format attack in Windows

# JKF 04/01/2005 More Microsoft security vulnerabilities
deny	\.bmp$			Windows bitmap file security vulnerability					Possible buffer overflow in Windows
deny	\.ico$			Windows icon file security vulnerability					Possible buffer overflow in Windows
deny	\.ani$			Windows animated cursor file security vulnerability				Possible buffer overflow in Windows
deny	\.cur$			Windows cursor file security vulnerability					Possible buffer overflow in Windows
deny	\.hlp$			Windows help file security vulnerability					Possible buffer overflow in Windows

# These 4 are well known viruses.
deny	pretty\s+park\.exe$	"Pretty Park" virus								"Pretty Park" virus
deny	happy99\.exe$		"Happy" virus									"Happy" virus
deny	\.ceo$		WinEvar virus attachment							Often used by the WinEvar virus
deny	webpage\.rar$	I-Worm.Yanker virus attachment							Often used by the I-Worm.Yanker virus

# JKF 08/07/2005 Several virus scanners may miss this one
deny	\.cab$			Possible malicious Microsoft cabinet file					Cabinet files may hide viruses

# These are known to be mostly harmless.
allow	\.jpg$			-	-
allow	\.gif$			-	-
# .url is arguably dangerous, but I can't just ban it...
allow	\.url$			-	-
allow	\.vcf$			-	-
allow	\.txt$			-	-
allow	\.zip$			-	-
allow	\.t?gz$			-	-
allow	\.bz2$			-	-
allow	\.Z$			-	-
allow	\.rpm$			-	-
# PGP and GPG
allow	\.gpg$			-	-
allow	\.pgp$			-	-
allow	\.sit$			-	-
allow	\.asc$			-	-
# Macintosh archives
allow	\.hqx$			-	-
allow	\.sit.bin$		-	-
allow	\.sea$			-	-

# These are known to be dangerous in almost all cases.
deny	\.reg$		Possible Windows registry attack						Windows registry entries are very dangerous in email
deny	\.chm$		Possible compiled Help file-based virus						Compiled help files are very dangerous in email
# See http://office.microsoft.com/2000/articles/Out2ksecFAQ.htm for more info.
deny	\.cnf$		Possible SpeedDial attack							SpeedDials are very dangerous in email
deny	\.hta$		Possible Microsoft HTML archive attack						HTML archives are very dangerous in email
deny	\.ins$		Possible Microsoft Internet Comm. Settings attack				Windows Internet Settings are dangerous in email
deny	\.jse?$		Possible Microsoft JScript attack						JScript Scripts are dangerous in email
deny	\.job$		Possible Microsoft Task Scheduler attack					Task Scheduler requests are dangerous in email
deny	\.lnk$		Possible Eudora *.lnk security hole attack					Eudora *.lnk security hole attack
deny	\.ma[dfgmqrstvw]$	Possible Microsoft Access Shortcut attack				Microsoft Access Shortcuts are dangerous in email
deny	\.pif$		Possible MS-Dos program shortcut attack						Shortcuts to MS-Dos programs are very dangerous in email
deny	\.scf$		Possible Windows Explorer Command attack					Windows Explorer Commands are dangerous in email
deny	\.sct$		Possible Microsoft Windows Script Component attack				Windows Script Components are dangerous in email
deny	\.shb$		Possible document shortcut attack						Shortcuts Into Documents are very dangerous in email
deny	\.shs$		Possible Shell Scrap Object attack						Shell Scrap Objects are very dangerous in email
deny	\.vb[es]$	Possible Microsoft Visual Basic script attack					Visual Basic Scripts are dangerous in email
deny	\.ws[cfh]$	Possible Microsoft Windows Script Host attack					Windows Script Host files are dangerous in email
deny	\.xnk$		Possible Microsoft Exchange Shortcut attack					Microsoft Exchange Shortcuts are dangerous in email

# These are new dangerous attachment types according to Microsoft in
# http://support.microsoft.com/?kbid=883260
deny	\.cer$		Dangerous Security Certificate (according to Microsoft)				Dangerous attachment according to Microsoft Q883260
deny	\.its$		Dangerous Internet Document Set (according to Microsoft)			Dangerous attachment according to Microsoft Q883260
deny	\.mau$		Dangerous attachment type (according to Microsoft)				Dangerous attachment according to Microsoft Q883260
deny	\.md[az]$	Dangerous attachment type (according to Microsoft)				Dangerous attachment according to Microsoft Q883260
deny	\.prf$		Dangerous Outlook Profile Settings (according to Microsoft)			Dangerous attachment according to Microsoft Q883260
deny	\.pst$		Dangerous Office Data File (according to Microsoft)				Dangerous attachment according to Microsoft Q883260
deny	\.tmp$		Dangerous Temporary File (according to Microsoft)				Dangerous attachment according to Microsoft Q883260
deny	\.vsmacros$	Dangerous Visual Studio Macros (according to Microsoft)				Dangerous attachment according to Microsoft Q883260
deny	\.vs[stw]$	Dangerous attachment type (according to Microsoft)				Dangerous attachment according to Microsoft Q883260
deny	\.ws$		Dangerous Windows Script (according to Microsoft)				Dangerous attachment according to Microsoft Q883260


# These 2 added by popular demand - Very often used by viruses
deny	\.com$		Windows/DOS Executable								Executable DOS/Windows programs are dangerous in email
deny	\.exe$		Windows/DOS Executable								Executable DOS/Windows programs are dangerous in email

# These are very dangerous and have been used to hide viruses
deny	\.scr$		Possible virus hidden in a screensaver						Windows Screensavers are often used to hide viruses
deny	\.bat$		Possible malicious batch file script						Batch files are often malicious
deny	\.cmd$		Possible malicious batch file script						Batch files are often malicious
deny	\.cpl$		Possible malicious control panel item						Control panel items are often used to hide viruses
deny	\.mhtml$	Possible Eudora meta-refresh attack						MHTML files can be used in an attack against Eudora

# Deny filenames ending with CLSID's
deny	\{[a-hA-H0-9-]{25,}\}	Filename trying to hide its real type				Files containing  CLSID's are trying to hide their real type

# Deny filenames with lots of contiguous white space in them.
deny	\s{10,}		Filename contains lots of white space						A long gap in a name is often used to hide part of it

# Allow repeated file extension, e.g. blah.zip.zip
allow	(\.[a-z0-9]{3})\1$	-	-

# Deny all other double file extensions. This catches any hidden filenames.
deny	\.[a-z][a-z0-9]{2,3}\s*\.[a-z0-9]{3}$	Found possible filename hiding				Attempt to hide real filename extension

