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# SpamAssassin rules file: header tests # # Please don't modify this file as your changes will be overwritten with # the next update. Use @@LOCAL_RULES_DIR@@/local.cf instead. # See 'perldoc Mail::SpamAssassin::Conf' for details. # # <@LICENSE> # Copyright 2004 Apache Software Foundation # # Licensed 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. # </@LICENSE> # ########################################################################### require_version @@VERSION@@ header HEAD_LONG eval:check_for_long_header() describe HEAD_LONG Message headers are very long header NO_REAL_NAME From =~ /^["\s]*\<?\S+\@\S+\>?\s*$/ describe NO_REAL_NAME From: does not include a real name header FROM_ENDS_IN_NUMS From =~ /\d\d\@/ describe FROM_ENDS_IN_NUMS From: ends in numbers header FROM_STARTS_WITH_NUMS From =~ /^\d\d/ describe FROM_STARTS_WITH_NUMS From: starts with nums # note: anchored for speed header FROM_HAS_MIXED_NUMS From =~ /(?:^|\D)\d+[a-z]+\d+\S*\@/i describe FROM_HAS_MIXED_NUMS From: contains numbers mixed in with letters # idea from Robert Menschel <RMSA@Menschel.net> header FROM_HAS_MIXED_NUMS3 From:addr =~ /^[a-z]+\d+[a-z]+\d+[a-z]+\w*\@/i describe FROM_HAS_MIXED_NUMS3 From: contains numbers mixed in with letters # Faked addresses tend to come from big public sites. Stats show that # 5 digits is enough to get a 1.0 s/o ratio; 4 is too low (probably due # to folks called "jmason2002@yahoo.com" for example). header ADDR_NUMS_AT_BIGSITE ALL =~ /^(To|From|Cc|Reply-To):\s*<?\S+\d{5,}\@(?:aol|bigfoot|compuserve|excite|hotmail|juno|prodigy|yahoo)\.(?:com|net|org)/mi describe ADDR_NUMS_AT_BIGSITE Uses an address with lots of numbers, at a big ISP header __FROM_JUST_NUMBER From:addr =~ /^\d+\@/ header __FROM_PHONE From:addr =~ /^\d{3}(?:[-.]?\d{3}[-.]?\d{4}|\d{7})\@/ meta FROM_ALL_NUMS (__FROM_JUST_NUMBER && !__FROM_PHONE) describe FROM_ALL_NUMS From an address that is all numbers (non-phone) header FROM_OFFERS From:addr =~ /\@\S*offers(?![eo]n\b)/i describe FROM_OFFERS From address is "at something-offers" header FROM_NO_USER From =~ /(?:^\@|<\@| \@[^\)<]*$|<>)/ [if-unset: unset@unset.unset] describe FROM_NO_USER From: has no local-part before @ sign header TO_NO_USER To =~ /(?:^\@|<\@| \@[^\)<]*$|<>)/ [if-unset: unset@unset.unset] describe TO_NO_USER To: has no local-part before @ sign header TO_EMPTY To =~ /^\s*$/ [if-unset: UNSET] describe TO_EMPTY To: is empty header REPLY_TO_EMPTY Reply-To =~ /^\s*$/ [if-unset: UNSET] describe REPLY_TO_EMPTY Reply-To: is empty header TO_ADDRESS_EQ_REAL To =~ /^\s*"([^"@]+\@[^"@]+)"\s+<\1>\s*$/i describe TO_ADDRESS_EQ_REAL To: repeats address as real name # NOTE: this is what 100% valid undisclosed-recipients mails look like. # If this gets a high score, that's a bug! header UNDISC_RECIPS To =~ /^undisclosed-recipients?:\s*;$/ describe UNDISC_RECIPS Valid-looking To "undisclosed-recipients" # also 100% valid header FAKED_UNDISC_RECIPS To =~ /undisclosed[_ ]*recipient(?:s[^:]|[^s])/i describe FAKED_UNDISC_RECIPS Faked To "Undisclosed-Recipients" header PLING_QUERY Subject =~ /\?.*!|!.*\?/ describe PLING_QUERY Subject has exclamation mark and question mark header SUBJ_HAS_UNIQ_ID eval:check_for_unique_subject_id() describe SUBJ_HAS_UNIQ_ID Subject contains a unique ID header SUBJ_HAS_SPACES Subject =~ /(?:\s{6}|\t\s|\s\t)\S/ describe SUBJ_HAS_SPACES Subject contains lots of white space header SUBJ_ALL_CAPS eval:subject_is_all_caps() describe SUBJ_ALL_CAPS Subject is all capitals header MSGID_SPAM_99X9XX99 MESSAGEID =~ /^<\d\d\d\d\d\d[a-z]\d[a-z][a-z]\d\d\$[a-z][a-z][a-z]\d\d\d\d\d\$\d\d\d\d\d\d\d\d\@/ describe MSGID_SPAM_99X9XX99 Spam tool Message-Id: (99x9xx99 variant) header MSGID_SPAM_ALPHA_NUM MESSAGEID =~ /<[A-Z]{7}-000[0-9]{10}\@[a-z]*>/ describe MSGID_SPAM_ALPHA_NUM Spam tool Message-Id: (alpha-numeric variant) header MSGID_SPAM_CAPS Message-ID =~ /^\s*<?[A-Z]+\@(?!(?:mailcity|whowhere)\.com)/ describe MSGID_SPAM_CAPS Spam tool Message-Id: (caps variant) header MSGID_SPAM_LETTERS Message-Id =~ /<[a-z]{5,}\@(\S+\.)+\S+>/ describe MSGID_SPAM_LETTERS Spam tool Message-Id: (letters variant) header MSGID_SPAM_ZEROES MESSAGEID =~ /<0000[0-9a-f]{8}\$0000[0-9a-f]{4}\$0000[0-9a-f]{4}\@/ describe MSGID_SPAM_ZEROES Spam tool Message-Id: (12-zeroes variant) header MSGID_NO_HOST MESSAGEID =~ /\@>(?:$|\s)/m describe MSGID_NO_HOST Message-Id has no hostname header MSGID_OUTLOOK_INVALID eval:check_outlook_message_id() describe MSGID_OUTLOOK_INVALID Message-Id is fake (in Outlook Express format) # catches a few spams missed by MSGID_OUTLOOK_INVALID header __HAS_OUTLOOK_IN_MAILER X-Mailer =~ /\bMSCRM\b|Microsoft (?:CDO|Outlook|Office Outlook)\b/ meta MSGID_DOLLARS (__OUTLOOK_DOLLARS_MSGID && !__HAS_OUTLOOK_IN_MAILER && !__UNUSABLE_MSGID) describe MSGID_DOLLARS Message-Id has pattern used in spam # bit of a ratware rule, but catches a bit more than just the one ratware header __MSGID_RANDY Message-ID =~ /<[a-z\d][a-z\d\$-]{10,29}[a-z\d]\@[a-z\d][a-z\d.]{3,12}[a-z\d]>/ # heuristic to eliminate most good Message-ID formats header __MSGID_OK_HEX Message-ID =~ /\b[a-f\d]{8}\b/ header __MSGID_OK_DIGITS Message-ID =~ /\d{10}/ header __MSGID_OK_HOST Message-ID =~ /\@(?:\D{2,}|(?:\d{1,3}\.){3}\d{1,3})>/ meta MSGID_RANDY (__MSGID_RANDY && !(__MSGID_OK_HEX || __MSGID_OK_HOST || __MSGID_OK_HOST)) describe MSGID_RANDY Message-Id has pattern used in spam # bug 3395 header MSGID_YAHOO_CAPS Message-ID =~ /<[A-Z]+\@yahoo.com>/ describe MSGID_YAHOO_CAPS Message-ID has ALLCAPS@yahoo.com ########################################################################### header __MSGID_BEFORE_RECEIVED ALL =~ /\nMessage-Id:.*\nReceived:/si header __MSGID_BEFORE_OKAY Message-Id =~ /\@[a-z0-9.-]+\.(?:yahoo|wanadoo)(?:\.[a-z]{2,3}){1,2}>/ meta MSGID_FROM_MTA_HEADER (__MSGID_BEFORE_RECEIVED && !__MSGID_BEFORE_OKAY) describe MSGID_FROM_MTA_HEADER Message-Id was added by a relay header MSGID_FROM_MTA_ID eval:message_id_from_mta() describe MSGID_FROM_MTA_ID Message-Id for external message added locally header MSGID_FROM_MTA_HOTMAIL Message-Id =~ /<MC\d{1,2}-F{1,2}\w{21,22}\@\S*hotmail\.com>/ describe MSGID_FROM_MTA_HOTMAIL Message-Id was added by a hotmail.com relay ########################################################################### header DATE_SPAMWARE_Y2K Date =~ /^[A-Z][a-z]{2}, \d\d [A-Z][a-z]{2} [0-6]\d \d\d:\d\d:\d\d [A-Z]{3}$/ describe DATE_SPAMWARE_Y2K Date header uses unusual Y2K formatting header INVALID_DATE Date !~ /^\s*(?:(?:Mon|Tue|Wed|Thu|Fri|Sat|Sun), )?[0-3 ]?[0-9] (?:Jan|Feb|Ma[ry]|Apr|Ju[nl]|Aug|Sep|Oct|Nov|Dec) (?:[12][901])?[0-9]{2} [0-2][0-9](?:\:[0-5][0-9]){1,2} (?:[+-][0-9]{4}|UT|[A-Z]{2,3}T)(?:\s+\(.*\))?\s*$/ [if-unset: Wed, 31 Jul 2002 16:41:57 +0200] describe INVALID_DATE Invalid Date: header (not RFC 2822) # allow +1300, NZ timezone header INVALID_DATE_TZ_ABSURD Date =~ /[-+](?:1[4-9]\d\d|[2-9]\d\d\d)$/ describe INVALID_DATE_TZ_ABSURD Invalid Date: header (timezone does not exist) header INVALID_TZ_CST ALL =~ /[+-]\d\d[30]0(?<!-0600|-0500|\+0800|\+0930|\+1030)\s+(?:\bCST\b|\(CST\))/ describe INVALID_TZ_CST Invalid date in header (wrong CST timezone) header INVALID_TZ_EST ALL =~ /[+-]\d\d[30]0(?<!-0500|-0300|\+1000|\+1100)\s+(?:\bEST\b|\(EST\))/ describe INVALID_TZ_EST Invalid date in header (wrong EST timezone) header INVALID_TZ_GMT ALL =~ /[+-]\d\d[30]0(?<![+-]0000)\s+(?:\b(?:GMT|UTC)\b(?![\w+-])|\((?:GMT|UTC)\))/ describe INVALID_TZ_GMT Invalid date in header (wrong GMT/UTC timezone) header DATE_IN_PAST_03_06 eval:check_for_shifted_date('-6', '-3') describe DATE_IN_PAST_03_06 Date: is 3 to 6 hours before Received: date header DATE_IN_PAST_06_12 eval:check_for_shifted_date('-12', '-6') describe DATE_IN_PAST_06_12 Date: is 6 to 12 hours before Received: date header DATE_IN_PAST_12_24 eval:check_for_shifted_date('-24', '-12') describe DATE_IN_PAST_12_24 Date: is 12 to 24 hours before Received: date header DATE_IN_PAST_24_48 eval:check_for_shifted_date('-48', '-24') describe DATE_IN_PAST_24_48 Date: is 24 to 48 hours before Received: date header DATE_IN_PAST_48_96 eval:check_for_shifted_date('-96', '-48') describe DATE_IN_PAST_48_96 Date: is 48 to 96 hours before Received: date header DATE_IN_PAST_96_XX eval:check_for_shifted_date('undef', '-96') describe DATE_IN_PAST_96_XX Date: is 96 hours or more before Received: date header DATE_IN_FUTURE_03_06 eval:check_for_shifted_date('3', '6') describe DATE_IN_FUTURE_03_06 Date: is 3 to 6 hours after Received: date header DATE_IN_FUTURE_06_12 eval:check_for_shifted_date('6', '12') describe DATE_IN_FUTURE_06_12 Date: is 6 to 12 hours after Received: date header DATE_IN_FUTURE_12_24 eval:check_for_shifted_date('12', '24') describe DATE_IN_FUTURE_12_24 Date: is 12 to 24 hours after Received: date header DATE_IN_FUTURE_24_48 eval:check_for_shifted_date('24', '48') describe DATE_IN_FUTURE_24_48 Date: is 24 to 48 hours after Received: date header DATE_IN_FUTURE_48_96 eval:check_for_shifted_date('48', '96') describe DATE_IN_FUTURE_48_96 Date: is 48 to 96 hours after Received: date header DATE_IN_FUTURE_96_XX eval:check_for_shifted_date('96', 'undef') describe DATE_IN_FUTURE_96_XX Date: is 96 hours or more after Received: date header UNRESOLVED_TEMPLATE ALL =~ /^(?!(?i:X-UIDL|X-Face|To|Cc|From|Subject|References|In-Reply-To|(?:X-|Resent-|X-Original-)?Message-Id):)[\w-]{1,24}:(?:[^\n]{0,100}|\n[ \t]){0,2}%[A-Z][A-Z_-]/m describe UNRESOLVED_TEMPLATE Headers contain an unresolved template ########################################################################### # illegal characters that should be MIME encoded # might want to exempt users using languages that don't use Latin # alphabets, but do it in the eval header SUBJ_ILLEGAL_CHARS eval:check_illegal_chars('Subject','0.00','2') describe SUBJ_ILLEGAL_CHARS Subject contains too many raw illegal characters header FROM_ILLEGAL_CHARS eval:check_illegal_chars('From','0.20','2') describe FROM_ILLEGAL_CHARS From contains too many raw illegal characters header HEAD_ILLEGAL_CHARS eval:check_illegal_chars('ALL','0.005','2') describe HEAD_ILLEGAL_CHARS Header contains too many raw illegal characters ########################################################################### # ADV tags in various languages header ENGLISH_UCE_SUBJECT Subject =~ /^[^0-9a-z]*adv(?:ert)?\b/i describe ENGLISH_UCE_SUBJECT Subject contains an English UCE tag # alan premselaar <alien@12inch.com>, see SpamAssassin-talk list 2003-03 # quinlan: 2003-03-23 here are more generic Japanese iso-2022-jp codes # ("not yet acceptance" or "email") + "announcement" # FWIW, according to Peter Evans, this should be sufficient to catch the # UCE tag and a common attempt at evasion (using the "sue" instead of # "mi" Chinese character). header JAPANESE_UCE_SUBJECT Subject =~ /\e\$B.*(?:L\$>5Bz|EE;R%a!<%k)9-9p/ describe JAPANESE_UCE_SUBJECT Subject contains a Japanese UCE tag # quinlan: "advertisement" in Russian KOI8-R # (no longer common, but worth noting in future) #header RUSSIAN_UCE_SUBJECT Subject =~ /\xf0\xe5\xea\xeb\xe0\xec\xf3/ #describe RUSSIAN_UCE_SUBJECT Subject contains a Russian UCE tag # Korean UCE Subject: lines are usually 8-bit, but are occasionally encoded # with quoted-printable or base64. # # \xbc\xba\xc0\xce means "adult" # \xb1\xa4\xb0\xed means "advertisement" # \xc1\xa4\xba\xb8 means "information" # \xc8\xab\xba\xb8 means "publicity" # # Each two byte sequence is one Korean letter; the spaces and periods are # sometimes used to obscure the words. \xb1\xa4\xb0\xed is the most common # tag and is sometimes very obscured so we look harder. # header KOREAN_UCE_SUBJECT Subject =~ /[({[<][. ]*(?:\xbc\xba[. ]*\xc0\xce[. ]*)?(?:\xb1\xa4(?:[. ]*|[\x00-\x7f]{0,3})\xb0\xed|\xc1\xa4[. ]*\xba\xb8|\xc8\xab[. ]*\xba\xb8)[. ]*[)}\]>]/ describe KOREAN_UCE_SUBJECT Subject: contains Korean unsolicited email tag ########################################################################### header FROM_AND_TO_SAME eval:check_for_from_to_same() describe FROM_AND_TO_SAME From and To are the same, but not exactly header FORGED_RCVD_HELO eval:check_for_forged_received_helo() describe FORGED_RCVD_HELO Received: contains a forged HELO header RCVD_HELO_IP_MISMATCH eval:helo_ip_mismatch() describe RCVD_HELO_IP_MISMATCH Received: HELO and IP do not match, but should header RCVD_NUMERIC_HELO eval:check_for_numeric_helo() describe RCVD_NUMERIC_HELO Received: contains an IP address used for HELO header RCVD_ILLEGAL_IP eval:check_for_illegal_ip() describe RCVD_ILLEGAL_IP Received: contains illegal IP address # no legit mailer claims that their mailserver has no name # overlaps with RCVD_DOUBLE_IP*, but let's see how it is scored header RCVD_BY_IP Received =~ /\bby\s+\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}(?<!127\.0\.0\.1)\b/ describe RCVD_BY_IP Received by mail server with no name # two reliable signatures header __DOUBLE_IP_SPAM_1 Received =~ /from \[\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\] by \d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3} with/ header __DOUBLE_IP_SPAM_2 Received =~ /from\s+\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\s+by\s+\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3};/ # loose match header __DOUBLE_IP_LOOSE Received =~ /(?:\b(?:from|by)\b.{1,4}\b\d{1,3}[._-]\d{1,3}[._-]\d{1,3}[._-]\d{1,3}(?<!127\.0\.0\.1)\b.{0,4}){2}/i # spam signature meta RCVD_DOUBLE_IP_SPAM (__DOUBLE_IP_SPAM_1 || __DOUBLE_IP_SPAM_2) describe RCVD_DOUBLE_IP_SPAM Bulk email fingerprint (double IP) found # other matches meta RCVD_DOUBLE_IP_LOOSE (__DOUBLE_IP_LOOSE && !RCVD_DOUBLE_IP_SPAM) describe RCVD_DOUBLE_IP_LOOSE Received: by and from look like IP addresses header FORGED_AOL_RCVD eval:check_for_fake_aol_relay_in_rcvd() describe FORGED_AOL_RCVD Received forged, contains fake AOL relays header FORGED_TELESP_RCVD Received =~ /\.(?!br).. \(\d+-\d+-\d+-\d+\.dsl\.telesp\.net\.br / describe FORGED_TELESP_RCVD Contains forged hostname for a DSL IP in Brazil # a forged Hotmail message; host HELO'd as hotmail.com, but it wasn't header FORGED_HOTMAIL_RCVD eval:check_for_forged_hotmail_received_headers() describe FORGED_HOTMAIL_RCVD Forged hotmail.com 'Received:' header found # this, by comparison is more common: from was @hotmail.com, but it wasn't header FORGED_HOTMAIL_RCVD2 eval:check_for_no_hotmail_received_headers() describe FORGED_HOTMAIL_RCVD2 hotmail.com 'From' address, but no 'Received:' header FORGED_EUDORAMAIL_RCVD eval:check_for_forged_eudoramail_received_headers() describe FORGED_EUDORAMAIL_RCVD Forged eudoramail.com 'Received:' header found header FORGED_YAHOO_RCVD eval:check_for_forged_yahoo_received_headers() describe FORGED_YAHOO_RCVD 'From' yahoo.com does not match 'Received' headers header FORGED_JUNO_RCVD eval:check_for_forged_juno_received_headers() describe FORGED_JUNO_RCVD 'From' juno.com does not match 'Received' headers header FORGED_GW05_RCVD eval:check_for_forged_gw05_received_headers() describe FORGED_GW05_RCVD Forged 'by gw05' 'Received:' header found # not used directly right now due to FPs; but CONFIRMED_FORGED turns it # into a 1.0 S/O rule anyway, so that's not a problem ;) # 2.626 3.6340 1.5251 0.704 0.34 1.44 FORGED_RCVD_TRAIL # 0.956 3.3890 0.0000 1.000 0.98 4.30 CONFIRMED_FORGED header __FORGED_RCVD_TRAIL eval:check_for_forged_received_trail() # forgery meta-rules: more reliable than their inputs meta CONFIRMED_FORGED (__FORGED_RCVD_TRAIL && (FORGED_AOL_RCVD || FORGED_HOTMAIL_RCVD || FORGED_EUDORAMAIL_RCVD || FORGED_YAHOO_RCVD || FORGED_JUNO_RCVD || FORGED_GW05_RCVD || FORGED_MX_HOTMAIL)) describe CONFIRMED_FORGED Received headers are forged meta MULTI_FORGED ((FORGED_AOL_RCVD + FORGED_HOTMAIL_RCVD + FORGED_EUDORAMAIL_RCVD + FORGED_YAHOO_RCVD + FORGED_JUNO_RCVD + FORGED_GW05_RCVD) > 1) describe MULTI_FORGED Received headers indicate multiple forgeries header NONEXISTENT_CHARSET Content-Type =~ /charset=.?DEFAULT/ describe NONEXISTENT_CHARSET Character set doesn't exist header CHARSET_FARAWAY_HEADER eval:check_for_faraway_charset_in_headers() describe CHARSET_FARAWAY_HEADER A foreign language charset used in headers tflags CHARSET_FARAWAY_HEADER userconf header X_PRIORITY_HIGH X-Priority =~ /^1/ describe X_PRIORITY_HIGH Sent with 'X-Priority' set to high header X_MSMAIL_PRIORITY_HIGH X-Msmail-Priority =~ /^High/ describe X_MSMAIL_PRIORITY_HIGH Sent with 'X-Msmail-Priority' set to high # this variant is local, using the Received hdr itself... header ROUND_THE_WORLD_LOCAL eval:check_for_round_the_world_received_helo() describe ROUND_THE_WORLD_LOCAL Received: says mail sent around the world (HELO) # and this one uses a DNS reverse lookup. so now we can use a version # of this test without a net connection, or in mass-check etc. header ROUND_THE_WORLD eval:check_for_round_the_world_received_revdns() describe ROUND_THE_WORLD Received: says mail sent around the world (DNS) tflags ROUND_THE_WORLD net header MISSING_DATE Date =~ /^UNSET$/ [if-unset: UNSET] describe MISSING_DATE Missing Date: header # this is a quite common false positive, as it's legal to remove a To but leave # a CC. so don't score it high. header MISSING_HEADERS eval:check_for_missing_to_header() describe MISSING_HEADERS Missing To: header header __HAS_SUBJECT exists:Subject meta MISSING_SUBJECT !__HAS_SUBJECT describe MISSING_SUBJECT Missing Subject: header header SUSPICIOUS_RECIPS eval:similar_recipients('0.65','undef') describe SUSPICIOUS_RECIPS Similar addresses in recipient list header SORTED_RECIPS eval:sorted_recipients() describe SORTED_RECIPS Recipient list is sorted by address header GAPPY_SUBJECT Subject =~ /\b(?:[a-z]([-_. =~\/:,*!\@\#\$\%\^&+;\"\'<>\\])\1{0,2}){4,}/i describe GAPPY_SUBJECT Subject: contains G.a.p.p.y-T.e.x.t ### header existence tests (description is added automatically) # X-Fix example: NTMail fixed non RFC822 compliant EMail message # # X-PMFLAGS is all caps # # Headers that seem to only be used by a single spamming software and # are found together in the same message: # 1. X-MailingID and X-ServerHost # 2. X-Stormpost-To and X-List-Unsubscribe # # not spammish: X-EM-Registration, X-EM-Version, X-Antiabuse, X-List-Host, # X-Message-Id # bad FP rate: Comment, Date-warning header X_LIBRARY exists:X-Library describe X_LIBRARY Message has X-Library header header __HAS_MIMEOLE exists:X-MimeOLE header __HAS_MSMAIL_PRI exists:X-MSMail-Priority header __HAS_SQUIRRELMAIL_IN_MAILER X-Mailer =~ /SquirrelMail\b/ meta MISSING_MIMEOLE (__HAS_MSMAIL_PRI && !__HAS_MIMEOLE && !__HAS_SQUIRRELMAIL_IN_MAILER) describe MISSING_MIMEOLE Message has X-MSMail-Priority, but no X-MimeOLE header __HAS_X_MAILER exists:X-Mailer header __IS_EXCH X-MimeOLE =~ /Produced By Microsoft Exchange V/ header __HAS_X_PRIORITY exists:X-Priority header __USER_AGENT exists:User-Agent meta PRIORITY_NO_NAME ((__HAS_X_PRIORITY || __HAS_MSMAIL_PRI) && !__HAS_X_MAILER && !__IS_EXCH && !__USER_AGENT) describe PRIORITY_NO_NAME Message has priority, but no X-Mailer/User-Agent header SUBJ_AS_SEEN Subject =~ /\bAs Seen/i describe SUBJ_AS_SEEN Subject contains "As Seen" header SUBJ_DOLLARS Subject =~ /^\$[0-9.,]+\b/ describe SUBJ_DOLLARS Subject starts with dollar amount header SUBJ_FOR_ONLY Subject =~ /For Only/i describe SUBJ_FOR_ONLY Subject contains "For Only" header SUBJ_FREE_CAP Subject =~ /FRE{2,}|F.R.E.E\b/ describe SUBJ_FREE_CAP Subject contains "FREE" in CAPS header SUB_FREE_OFFER Subject =~ /^fre{2,}\b/i describe SUB_FREE_OFFER Subject starts with "Free" header SUBJ_GUARANTEED Subject =~ /^guaranteed|(?-i:GUARANTEE)/i describe SUBJ_GUARANTEED Subject GUARANTEED header SUB_HELLO Subject =~ /^hello\b/i describe SUB_HELLO Subject starts with "Hello" header SUBJ_LIFE_INSURANCE Subject =~ /life\s+insurance/i describe SUBJ_LIFE_INSURANCE Subject includes "life insurance" header SUBJ_YOUR_DEBT Subject =~ /Your (?:Bills|Debt|Credit)/i describe SUBJ_YOUR_DEBT Subject contains "Your Bills" or similar header SUBJ_YOUR_FAMILY Subject =~ /Your Family/i describe SUBJ_YOUR_FAMILY Subject contains "Your Family" header SUBJ_YOUR_OWN Subject =~ /Your Own/i describe SUBJ_YOUR_OWN Subject contains "Your Own" # the real services never HELO as 'foo.com', instead 'mail.foo.com' or # something like that. Note: be careful when expanding this... legit dotcom # HELOers include: hotmail.com, drizzle.com, lockergnome.com. header RCVD_FAKE_HELO_DOTCOM Received =~ /^from (?:msn|yahoo|yourwebsite|lycos|excite|cs|aol|localhost|koreanmail|allexecs|mydomain|juno|eudoramail|compuserve|desertmail|excite|caramail)\.com \(/m describe RCVD_FAKE_HELO_DOTCOM Received contains a faked HELO hostname header ADDRESS_IN_SUBJECT eval:check_for_to_in_subject('address') describe ADDRESS_IN_SUBJECT To: address appears in Subject header SUBJECT_DIET Subject =~ /\bLose .*(?:pounds|lbs|weight)/i describe SUBJECT_DIET Subject talks about losing pounds header EXTRA_MPART_TYPE Content-Type =~ /(?:\s*multipart\/)?.* type=/i describe EXTRA_MPART_TYPE Header has extraneous Content-type:...type= entry header TO_RECIP_MARKER To =~ /\#recipient\#/ describe TO_RECIP_MARKER To header contains 'recipient' marker # MIME boundary tests; spam tools use distinctive patterns. header MIME_BOUND_DD_DIGITS Content-Type =~ /boundary=\"--\d+\"/ describe MIME_BOUND_DD_DIGITS Spam tool pattern in MIME boundary header MIME_BOUND_DIGITS_7 Content-Type =~ /boundary=\d{9}\.\d{13}/ describe MIME_BOUND_DIGITS_7 Spam tool pattern in MIME boundary header MIME_BOUND_DIGITS_15 Content-Type =~ /boundary=\"\d{15,}\"/ describe MIME_BOUND_DIGITS_15 Spam tool pattern in MIME boundary header MIME_BOUND_MANY_HEX Content-Type =~ /boundary="[\da-f]{8}(?:-[\da-f]{4}){3}-[\da-f]{12}"/ describe MIME_BOUND_MANY_HEX Spam tool pattern in MIME boundary header __NEXTPART_ALL Content-Type =~ /NextPart/ header __NEXTPART_NORMAL Content-Type =~ /="(?:----_?=_)?NextPart_[\dA-F]{3}(_[\dA-F]{3,8})?_[\dA-F]{8}\.[\dA-F]{8}"/ meta MIME_BOUND_NEXTPART (__NEXTPART_ALL && !__NEXTPART_NORMAL) describe MIME_BOUND_NEXTPART Spam tool pattern in MIME boundary header MIME_BOUND_RKFINDY Content-Type =~ /boundary=\"=_NextPart_2rfkindysadvnqw3nerasdf\"/ describe MIME_BOUND_RKFINDY Spam tool pattern in MIME boundary (rfkindy) # note: the first alternation is anchored for speed header TO_MALFORMED To !~ /(?:^|[^\S"])(?:(?:\"[^\"]+\"|\S+)\@\S+\.\S+|^\s*.+:\s*;|^\s*\"[^\"]+\":\s*;|^\s*\([^\)]*\)\s*$|<\S+(?:\!\S+){1,}>|^\s*$)/ [if-unset: unset@unset.unset] describe TO_MALFORMED To: has a malformed address # Most/all of these require that From addresses do not start with numbers. header FROM_NUM_AT_WEBMAIL From:addr =~ /^\d\S+\@(?:msn\.com|flashmail\.com|mailexcite\.com|prodigy\.net|yahoo\.\S+|hotmail\.com|eudoramail\.com|aol\.com|excite\.com|email\.com|earthlink\.net|geocities\.com|hknetmail\.com|angelfire\.com)/i describe FROM_NUM_AT_WEBMAIL From address is webmail, but starts with a number header FROM_WEBMAIL_END_NUMS6 From:addr =~ /\d\d\d\d\d\d\@(?:aol|msn|bigfoot|compuserve|excite|hotmail|juno|prodigy|yahoo)\.(?:com|net|org)/i describe FROM_WEBMAIL_END_NUMS6 From webmail service and address ends in numbers header ADDR_FREE From =~ /\b(?-i:F)ree(?-i:[ A-Z]).*</i describe ADDR_FREE From Address contains FREE # common spam-dropping: To: C:\VICTIMS.txt@yourmx.org header TO_TXT To =~ /\.txt[\'\"]?\@/i describe TO_TXT Sent to a text file header CHINA_HEADER ALL =~ /\@china\.com/i describe CHINA_HEADER Involves 'china.com' header __CD exists:Content-Disposition header __CT exists:Content-Type header __CTE exists:Content-Transfer-Encoding header __MIME_VERSION exists:MIME-Version header __CT_TEXT_PLAIN Content-Type =~ /^text\/plain\b/i meta MIME_HEADER_CTYPE_ONLY (!__CD && !__CTE && __CT && !__MIME_VERSION && !__CT_TEXT_PLAIN) describe MIME_HEADER_CTYPE_ONLY 'Content-Type' found without required MIME headers header WITH_LC_SMTP Received =~ /\swith\ssmtp;\s/ describe WITH_LC_SMTP Received line contains spam-sign (lowercase smtp) header FROM_NO_LOWER From:addr !~ /[a-z]/ [if-unset: x@example.com] describe FROM_NO_LOWER From address has no lower-case characters header SUBJ_BUY Subject =~ /^buy/i describe SUBJ_BUY Subject line starts with Buy or Buying header __FROM_HAS_UNDERLINE_NUMS From =~ /_\S?(?:[a-z]+\w*?\d+|\d+\w*?[a-z]+)\w*\@/i meta FROM_HAS_ULINE_NUMS (!REPLY_TO_ULINE_NUMS && __FROM_HAS_UNDERLINE_NUMS) describe FROM_HAS_ULINE_NUMS From: contains an underline and numbers/letters header NIGERIAN_SUBJECT1 Subject =~ /^(?:Re:|\[.{1,10}\])?\s*(?:(?:very )?URGENT|ATTENTION)\s*$/i describe NIGERIAN_SUBJECT1 Subject is indicative of a Nigerian spam header NIGERIAN_SUBJECT2 Subject =~ /^(?:Re:|\[.{1,10}\])?\s*(?:very )?urgent\s+(?:(?:and|&)\s+)?(?:confidential|assistance|business|attention|reply|response|help)\b/i describe NIGERIAN_SUBJECT2 Subject is indicative of a Nigerian spam # this code uses an access database (sendmail, postfix, etc.) # Since you need to actively create an accessdb to use it, the rule is # considered userconf and is disabled by default. header ACCESSDB eval:check_access_database('/etc/mail/access.db') describe ACCESSDB Message would have been caught by accessdb tflags ACCESSDB userconf # seems to be ratware header RCVD_AM_PM Received =~ /; [A-Z][a-z][a-z], \d{1,2} \d{4} \d{1,2}:\d\d:\d\d [AP]M [+-]\d{4}/ describe RCVD_AM_PM Received headers forged (AM/PM) header HEADER_COUNT_CTYPE eval:check_header_count_range('Content-Type','2','999') describe HEADER_COUNT_CTYPE Multiple Content-Type headers found header __USER_AGENT_MSN X-Mailer =~ /^MSN Explorer / header NO_RDNS_DOTCOM_HELO eval:check_for_no_rdns_dotcom_helo() describe NO_RDNS_DOTCOM_HELO Host HELO'd as a big ISP, but had no rDNS header X_ORIG_IP_NOT_IPV4 X-Originating-IP !~ /\[?(?:\d{1,3}\.){3}\d{1,3}\]?/ [if-unset: 0.0.0.0] describe X_ORIG_IP_NOT_IPV4 X-Originating-IP doesn't look like IPv4 address # match the format of a legit X-Auth-Warning header, and hit on fake ones # normal: "e4e.oac.uci.edu: foo owned process doing -bs" # fake: "bzgrdag, upaeqehv" header X_AUTH_WARN_FAKED X-Authentication-Warning !~ /^(\S+\.\S+): / [if-unset: host.example.net: foo owned process doing -bs] describe X_AUTH_WARN_FAKED X-Authentication-Warning header looks faked # host no longer exists according to administrator header FAKE_OUTBLAZE_RCVD Received =~ /\.mr\.outblaze\.com/ describe FAKE_OUTBLAZE_RCVD Received header contains faked 'mr.outblaze.com' # domains never longer used for email, confirmed by administrator header FROM_NONSENDING_DOMAIN From:addr =~ /\@(?:altavista\.com|eudora\.com)$/i describe FROM_NONSENDING_DOMAIN Message is from domain that never sends email header SUBJ_2_NUM_PARENS Subject =~ /^\(\d+\).*\(\d+\)\s*$/ describe SUBJ_2_NUM_PARENS Subject contains common spam sign (2 numbers) 
