# Exim filter
-## Version: 0.14
-# $Id: system_filter.exim,v 1.6 2001/08/15 10:02:33 nigel Exp $
+## Version: 0.16
+# $Id: system_filter.exim,v 1.8 2001/09/19 10:20:22 nigel Exp $
## Exim system filter to refuse potentially harmful payloads in
## mail messages
## -----------------------------------------------------------------------
# Look for single part MIME messages with suspicious name extensions
# Check Content-Type header using quoted filename [content_type_quoted_fn_match]
-if $header_content-type: matches "(?:file)?name=(\"[^\"]+\\\\.(?:vb[se]|ws[fh]|jse?|exe|com|cmd|shs|hta|bat|scr|lnk|pif)\")"
+if $header_content-type: matches "(?:file)?name=(\"[^\"]+\\\\.(?:ad[ep]|ba[st]|chm|cmd|com|cpl|crt|eml|exe|hlp|hta|in[fs]|isp|jse?|lnk|md[be]|ms[cipt]|pcd|pif)|reg|scr|sct|shs|url|vb[se]|ws[fhc])\")"
then
fail text "This message has been rejected because it has\n\
potentially executable content $1\n\
seen finish
endif
# same again using unquoted filename [content_type_unquoted_fn_match]
-if $header_content-type: matches "(?:file)?name=(.+\\\\.(?:vb[se]|ws[fh]|jse?|exe|com|cmd|shs|hta|bat|scr|lnk|pif))"
+if $header_content-type: matches "(?:file)?name=(\\\\S+\\\\.(?:ad[ep]|ba[st]|chm|cmd|com|cpl|crt|eml|exe|hlp|hta|in[fs]|isp|jse?|lnk|md[be]|ms[cipt]|pcd|pif)|reg|scr|sct|shs|url|vb[se]|ws[fhc]))"
then
fail text "This message has been rejected because it has\n\
potentially executable content $1\n\
# in emails. These were used as the basis for
# the ILOVEYOU virus and its variants - many many varients
# Quoted filename - [body_quoted_fn_match]
-if $message_body matches "(?:Content-(?:Type:(?>\\\\s*)[\\\\w-]+/[\\\\w-]+|Disposition:(?>\\\\s*)attachment);(?>\\\\s*)(?:file)?name=|begin(?>\\\\s+)[0-7]{3,4}(?>\\\\s+))(\"[^\"]+\\\\.(?:vb[se]|ws[fh]|jse?|exe|com|cmd|shs|hta|bat|scr|lnk|pif)\")[\\\\s;]"
+if $message_body matches "(?:Content-(?:Type:(?>\\\\s*)[\\\\w-]+/[\\\\w-]+|Disposition:(?>\\\\s*)attachment);(?>\\\\s*)(?:file)?name=|begin(?>\\\\s+)[0-7]{3,4}(?>\\\\s+))(\"[^\"]+\\\\.(?:ad[ep]|ba[st]|chm|cmd|com|cpl|crt|eml|exe|hlp|hta|in[fs]|isp|jse?|lnk|md[be]|ms[cipt]|pcd|pif)|reg|scr|sct|shs|url|vb[se]|ws[fhc])\")[\\\\s;]"
then
fail text "This message has been rejected because it has\n\
a potentially executable attachment $1\n\
seen finish
endif
# same again using unquoted filename [body_unquoted_fn_match]
-if $message_body matches "(?:Content-(?:Type:(?>\\\\s*)[\\\\w-]+/[\\\\w-]+|Disposition:(?>\\\\s*)attachment);(?>\\\\s*)(?:file)?name=|begin(?>\\\\s+)[0-7]{3,4}(?>\\\\s+))(.+\\\\.(?:vb[se]|ws[fh]|jse?|exe|com|cmd|shs|hta|bat|scr|lnk|pif))[\\\\s;]"
+if $message_body matches "(?:Content-(?:Type:(?>\\\\s*)[\\\\w-]+/[\\\\w-]+|Disposition:(?>\\\\s*)attachment);(?>\\\\s*)(?:file)?name=|begin(?>\\\\s+)[0-7]{3,4}(?>\\\\s+))(\\\\S+\\\\.(?:ad[ep]|ba[st]|chm|cmd|com|cpl|crt|eml|exe|hlp|hta|in[fs]|isp|jse?|lnk|md[be]|ms[cipt]|pcd|pif)|reg|scr|sct|shs|url|vb[se]|ws[fhc]))[\\\\s;]"
then
fail text "This message has been rejected because it has\n\
a potentially executable attachment $1\n\
# library files, cutting down on manual duplication.
# Changed \w in filename detection to . - dodges locale problems
# Explicit application of GPL after queries on license status
+# 0.15 17 August, 2001
+# Changed the . in filename detect to \S (stops it going mad)
+# 0.16 19 September, 2001
+# Pile of new extensions including the eml in current use
#
#### Install Notes
#
# (?:file)?name= # filename=/name=
# |begin (?>\s+) [0-7]{3,4} (?>\s+)) # begin octal-mode
# (\"[^\"]+\. # quoted filename.
-# (?:vb[se] # list of extns
-# |ws[fh]
-# |jse?
-# |exe
-# |com
+# (?:ad[ep] # list of extns
+# |ba[st]
+# |chm
# |cmd
-# |shs
+# |com
+# |cpl
+# |crt
+# |eml
+# |exe
+# |hlp
# |hta
-# |bat
-# |scr
+# |in[fs]
+# |isp
+# |jse?
# |lnk
+# |md[be]
+# |ms[cipt]
+# |pcd
# |pif)
+# |reg
+# |scr
+# |sct
+# |shs
+# |url
+# |vb[se]
+# |ws[fhc])
# \" # end quote
# ) # end of filename capture
# [\s;] # trailing ;/space/newline