# HG changeset patch # User IBBoard # Date 1486673670 0 # Node ID dae1088dd218757f8200ac325c4ff622d737a776 # Parent ce6aafd0880b21b0be7a6351476939c9d164a0d9 Add OLE detection to SpamAssassin without ClamAV Note: currently subject to https://github.com/JonathanThorpe/spamassassin-vba-macro/issues/15 diff -r ce6aafd0880b -r dae1088dd218 common/ole2macro.cf --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/common/ole2macro.cf Thu Feb 09 20:54:30 2017 +0000 @@ -0,0 +1,6 @@ +# Run VBA Macro checks without ClamAV +loadplugin OLE2Macro ole2macro.pm + +body MICROSOFT_OLE2MACRO eval:check_microsoft_ole2macro() +describe MICROSOFT_OLE2MACRO Has an attachment that contains an OLE2 Macro +score MICROSOFT_OLE2MACRO 4 diff -r ce6aafd0880b -r dae1088dd218 common/spamassassin-vba-macro-master/LICENSE --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/common/spamassassin-vba-macro-master/LICENSE Thu Feb 09 20:54:30 2017 +0000 @@ -0,0 +1,202 @@ + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + + TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + + 1. 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For instance ```/etc/spamassassin/conf.d/90_ole2macro.cf``` + +``` +loadplugin OLE2Macro ole2macro.pm + +body MICROSOFT_OLE2MACRO eval:check_microsoft_ole2macro() +describe MICROSOFT_OLE2MACRO Has an attachment that contains an OLE2 Macro +score MICROSOFT_OLE2MACRO 4 +``` + +In most cases, you will want to adjust the score accordingly, however, with a cut-off score of 5.5, 4.0 as described above has worked well in a production environment with diverse users. diff -r ce6aafd0880b -r dae1088dd218 common/spamassassin-vba-macro-master/ole2macro.pm --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/common/spamassassin-vba-macro-master/ole2macro.pm Thu Feb 09 20:54:30 2017 +0000 @@ -0,0 +1,207 @@ +# <@LICENSE> +# Licensed to the Apache Software Foundation (ASF) under one or more +# contributor license agreements. See the NOTICE file distributed with +# this work for additional information regarding copyright ownership. +# The ASF licenses this file to you under the Apache License, Version 2.0 +# (the "License"); you may not use this file except in compliance with +# the License. You may obtain a copy of the License at: +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# + +=head1 NAME + +OLE2Macro - Look for Macro Embedded Microsoft Word and Excel Documents + +=head1 SYNOPSIS + +loadplugin ole2macro.pm +body MICROSOFT_OLE2MACRO eval:check_microsoft_ole2macro() +score MICROSOFT_OLE2MACRO 4 + +=head1 DESCRIPTION + +Detects embedded OLE2 Macros embedded in Word and Excel Documents. Based on: +https://blog.rootshell.be/2015/01/08/searching-for-microsoft-office-files-containing-macro/ + +10/12/2015 - Jonathan Thorpe - jthorpe@conexim.com.au + +=back + +=cut + +package OLE2Macro; + +use Mail::SpamAssassin::Plugin; +use Mail::SpamAssassin::Logger; +use Mail::SpamAssassin::Util; +use IO::Uncompress::Unzip; +use IO::Scalar; + +use strict; +use warnings; +use bytes; +use re 'taint'; + +use vars qw(@ISA); +@ISA = qw(Mail::SpamAssassin::Plugin); + +#File types and markers +my $match_types = qr/(?:xls|xlt|pot|ppt|pps|doc|dot)$/; + +#Microsoft OOXML-based formats with Macros +my $match_types_xml = qr/(?:xlsm|xltm|xlsb|potm|pptm|ppsm|docm|dotm)$/; + +#Markers in the order in which they should be found. +my @markers = ("\xd0\xcf\x11\xe0", "\x00\x41\x74\x74\x72\x69\x62\x75\x74\x00"); + +# limiting the number of files within archive to process +my $archived_files_process_limit = 3; +# limiting the amount of bytes read from a file +my $file_max_read_size = 102400; +# limiting the amount of bytes read from an archive +my $archive_max_read_size = 1024000; + +# limiting the amount of bytes read from a file to determine MIME type +my $mime_max_read_size = 8; + + +my $has_mimeinfo = 0; +eval('use File::MimeInfo::Magic'); +if(!$@){ + $has_mimeinfo = 1; +} + +# constructor: register the eval rule +sub new { + my $class = shift; + my $mailsaobject = shift; + + # some boilerplate... + $class = ref($class) || $class; + my $self = $class->SUPER::new($mailsaobject); + bless ($self, $class); + + $self->register_eval_rule("check_microsoft_ole2macro"); + + return $self; +} + +sub check_microsoft_ole2macro { + my ($self, $pms) = @_; + + _check_attachments(@_) unless exists $pms->{nomacro_microsoft_ole2macro}; + return $pms->{nomacro_microsoft_ole2macro}; +} + +sub _match_markers { + my ($data) = @_; + + my $matched=0; + foreach(@markers){ + if(index($data, $_) > -1){ + $matched++; + } else { + last; + } + } + + return $matched == @markers; +} + +sub _is_zip { + my ($name, $part) = @_; + + if ($has_mimeinfo){ + my $contents_scalar = new IO::Scalar \$part->decode($mime_max_read_size); + my $mime_type = File::MimeInfo::Magic::magic($contents_scalar); + return($mime_type eq "application/zip"); + }else{ + return($name =~ /(?:zip)$/); + } +} + +sub _check_attachments { + my ($self, $pms) = @_; + + my $processed_files_counter = 0; + $pms->{nomacro_microsoft_ole2macro} = 0; + + foreach my $p ($pms->{msg}->find_parts(qr/./, 1)) { + my ($ctype, $boundary, $charset, $name) = + Mail::SpamAssassin::Util::parse_content_type($p->get_header('content-type')); + + + $name = lc($name || ''); + if ($name =~ $match_types) { + my $contents = $p->decode($file_max_read_size); + if(_match_markers($contents)){ + $pms->{nomacro_microsoft_ole2macro} = 1; + last; + } + } + + if (_is_zip($name, $p)) { + my $contents = $p->decode($archive_max_read_size); + my $z = new IO::Uncompress::Unzip \$contents; + + my $status; + my $buff; + my $zip_fn; + + if (defined $z) { + for ($status = 1; $status > 0; $status = $z->nextStream()) { + $zip_fn = lc $z->getHeaderInfo()->{Name}; + + #Parse these first as they don't need handling of the contents. + if ($zip_fn =~ $match_types_xml) { + $pms->{nomacro_microsoft_ole2macro} = 1; + last; + } elsif ($zip_fn =~ $match_types or $zip_fn eq "[content_types].xml") { + $processed_files_counter += 1; + if ($processed_files_counter > $archived_files_process_limit) { + dbg( "Stopping processing archive on file ".$z->getHeaderInfo()->{Name}.": processed files count limit reached\n" ); + last; + } + my $attachment_data = ""; + my $read_size = 0; + while (($status = $z->read( $buff )) > 0) { + $attachment_data .= $buff; + $read_size += length( $buff ); + if ($read_size > $file_max_read_size) { + dbg( "Stopping processing file ".$z->getHeaderInfo()->{Name}." in archive: processed file size overlimit\n" ); + last; + } + } + + #OOXML format + if($zip_fn eq "[content_types].xml"){ + if($attachment_data =~ /ContentType=["']application\/vnd.ms-office.vbaProject["']/i){ + $pms->{nomacro_microsoft_ole2macro} = 1; + last; + } + }else{ + if (_match_markers( $attachment_data )) { + $pms->{nomacro_microsoft_ole2macro} = 1; + last; + } + } + } + } + }else{ + dbg( "Unable to open ZIP file\n" ); + } + } elsif ($name =~ $match_types_xml) { + $pms->{nomacro_microsoft_ole2macro} = 1; + last; + } + } +} + +1; diff -r ce6aafd0880b -r dae1088dd218 manifests/templates.pp --- a/manifests/templates.pp Wed Jan 18 21:13:20 2017 +0000 +++ b/manifests/templates.pp Thu Feb 09 20:54:30 2017 +0000 @@ -656,6 +656,16 @@ source => 'puppet:///private/postfix/amavisd.conf', tag => 'av', } + file { '/etc/mail/spamassassin/ole2macro.cf': + ensure => present, + source => 'puppet:///common/ole2macro.cf', + tag => 'av', + } + file { '/etc/mail/spamassassin/ole2macro.pm': + ensure => present, + source => 'puppet:///common/spamassassin-vba-macro-master/ole2macro.pm', + tag => 'av', + } Package<| tag == 'av' |> -> File<| tag == 'av' |> File<| tag == 'av' |> { notify => Service['amavisd'],