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findspam.py
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findspam.py
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# -*- coding: utf-8 -*-
# noinspection PyCompatibility
import sys
import math
import regex
from difflib import SequenceMatcher
from urllib.parse import urlparse, unquote_plus
from itertools import chain
from collections import Counter
from datetime import datetime
import time
import os
import os.path as path
# noinspection PyPackageRequirements
import tld
# noinspection PyPackageRequirements
from tld.utils import TldDomainNotFound
import phonenumbers
import dns.resolver
import requests
import chatcommunicate
from helpers import log
import metasmoke_cache
from globalvars import GlobalVars
import blacklists
TLD_CACHE = []
DNS_CACHE = dict()
LINK_CACHE = dict()
LEVEN_DOMAIN_DISTANCE = 3
SIMILAR_THRESHOLD = 0.95
SIMILAR_ANSWER_THRESHOLD = 0.7
BODY_TITLE_SIMILAR_RATIO = 0.90
CHARACTER_USE_RATIO = 0.42
PUNCTUATION_RATIO = 0.42
REPEATED_CHARACTER_RATIO = 0.20
EXCEPTION_RE = r"^Domain (.*) didn't .*!$"
RE_COMPILE = regex.compile(EXCEPTION_RE)
COMMON_MALFORMED_PROTOCOLS = [
('httl://', 'http://'),
]
# These types of files frequently get caught as "misleading link"
SAFE_EXTENSIONS = {'htm', 'py', 'java', 'sh'}
SE_SITES_RE = r'(?:{sites})'.format(
sites='|'.join([
r'(?:[a-z]+\.)*stackoverflow\.com',
r'(?:{doms})\.com'.format(doms='|'.join(
[r'askubuntu', r'superuser', r'serverfault', r'stackapps', r'imgur'])),
r'mathoverflow\.net',
r'(?:[a-z]+\.)*stackexchange\.com']))
SE_SITES_DOMAINS = ['stackoverflow.com', 'askubuntu.com', 'superuser.com', 'serverfault.com',
'mathoverflow.net', 'stackapps.com', 'stackexchange.com', 'sstatic.net',
'imgur.com'] # Frequently catching FP
WHITELISTED_WEBSITES_REGEX = regex.compile(r"(?i)upload|\b(?:{})\b".format("|".join([
"yfrog", "gfycat", "tinypic", "sendvid", "ctrlv", "prntscr", "gyazo", r"youtu\.?be", "past[ie]", "dropbox",
"microsoft", "newegg", "cnet", "regex101", r"(?<!plus\.)google", "localhost", "ubuntu", "getbootstrap",
r"jsfiddle\.net", r"codepen\.io", "pastebin"
] + [se_dom.replace(".", r"\.") for se_dom in SE_SITES_DOMAINS])))
ASN_WHITELISTED_WEBSITES = [
"unity3d.com", "ffmpeg.org", "bitcoincore.org", "latex.codecogs.com",
"advancedcustomfields.com", "name.com", "businessbloomer.com",
"wkhtmltopdf.org", "thefreedictionary.com", "ruby-doc.org",
"site.com.br", "test.ooo-pnu.ru", "swift.org", "site2.com",
"rxweb.io", "tenforums.com", "rhydolabz.com", "javatpoint.com",
# ^^ top 20 FP hosts that get reported due to 'bad ASN', collated by regex parsing
# https://metasmoke.erwaysoftware.com/data/sql/queries/164-bad-asn-in-false-positives
# As of 2019-04-18, the following had >=6 ASN detections which were FP
"ampps.com", "bintray.com", "config.ru", "datetime.date", "myexample.com",
"mywiki.wooledge.org", "sevenforums.com", "ultimatefreehost.in", "wa.me", "web.com",
# As of 2019-04-18, the following had 5 ASN detections which were FP
"androidforums.com", "getclayton.com", "indeed.com", "math.net",
"mobilefirstplatform.ibmcloud.com", "ss.ms", "table.to",
# As of 2019-04-18, the following had 4 ASN detections which were FP
"code.kx.com", "daniweb.com", "files.catbox.moe", "greatrecipetips.com", "html5up.net",
"irc.freenode.net", "italian-stresser.online", "meteocaldas.com", "techpowerup.com",
"unit-conversion.info", "wicked.io",
# not being added: bitcoinofficial.org, learn-neural-networks.com
# As of 2019-04-18, the following had 3 ASN detections which were FP
"bankingifsccodes.com", "bethelp.byethost3.com", "calculator.net", "change.by",
"clover.com", "cognimem.com", "csde.epizy.com", "docker.bintray.io", "domaine.com",
"dreamstime.com", "embedded101.com", "emildeveloping.com", "extjs.eu", "fixer.io",
"fondation-zeitgeist.com", "form.media", "formcontact.esy.es", "godandscience.org",
"kajariaceramics.com", "macappstore.org", "maven.ibiblio.org", "nayuki.io", "nxos.org",
"pdf.datasheetcatalog.com", "php.info", "pool.sks-keyservers.net", "reg.ru", "scaan.in",
"shop.btownmedia.com", "smtp.sendgrid.net", "sysengineering.ru", "techspot.com",
"testking.com", "thecollegeroar.com", "ursuscode.com", "vwo.com",
# Not added:
# 000webhostapp.com This domain would be reasonable to add if it didn't also whitelist all subdomains.
# As of 2019-04-18, the following had 2 ASN detections which were FP, and appeared to be common.
"wikileaks.org",
# Additional added not as part of a systematic investigation:
"ntp.org", "cpu-world.com", "caniuse.com", "guru99.com", "fontawesome.com",
# Added to prevent having 3 detections on just the domain.
"writingexplained.org", "eitren.com"]
COUNTRY = [
# N Europe
"Iceland", "Denmark", "Sweden", "Norway",
# Oceania
"Australia", "New Zealand", "NewZealand",
]
if GlobalVars.perspective_key:
PERSPECTIVE = "https://commentanalyzer.googleapis.com/v1alpha1/comments:analyze?key=" + GlobalVars.perspective_key
PERSPECTIVE_THRESHOLD = 0.85 # conservative
# Flee before the ugly URL validator regex!
# We are using this, instead of a nice library like BeautifulSoup, because spammers are
# stupid and don't always know how to actually *link* their web site. BeautifulSoup misses
# those plain text URLs.
# https://gist.github.com/dperini/729294#gistcomment-1296121
URL_REGEX = regex.compile(
r"""((?:(?:https?|ftp)://)(?:\S+(?::\S*)?@)?(?:(?!(?:10|127)"""
r"""(?:\.\d{1,3}){3})(?!(?:169\.254|192\.168)(?:\.\d{1,3}){2}))"""
r"""(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])"""
r"""(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))"""
r"""|\b(?:(?:[A-Za-z\u00a1-\uffff0-9]-?)*[A-Za-z\u00a1-\uffff0-9]+)(?:\.(?:[A-Za-z\u00a1-\uffff0-9]-?)"""
r"""*[A-Za-z\u00a1-\uffff0-9]+)*(?:\.(?:[A-Za-z\u00a1-\uffff]{2,})))(?::\d{2,5})?(?:/\S*)?""", regex.U)
TAG_REGEX = regex.compile(r"</?[abcdehiklopsu][^>]*?>|\w+://", regex.U)
NUMBER_REGEX = regex.compile(r'(?<=\D|^)\+?(?:\d[\W_]*){8,19}\d(?=\D|$)', regex.U | regex.I)
UNIFORM = math.log(1 / 36)
UNIFORM_PRIOR = math.log(1 / 5)
ENGLISH = {
'a': -2.56940287968626,
'e': -2.6325365263400786,
'o': -2.9482912667071903,
'r': -2.9867566750238046,
'i': -3.043195438576378,
's': -3.053589802306065,
'n': -3.0696364572432233,
'1': -3.134872509228817,
't': -3.230441879550407,
'l': -3.2558408400221905,
'2': -3.4663376838336166,
'm': -3.4810979044444426,
'd': -3.5635447023561517,
'0': -3.5958227205042967,
'c': -3.6348280308631855,
'p': -3.6771505079154236,
'3': -3.7158848391017765,
'h': -3.7019152926538648,
'b': -3.74138548356748,
'u': -3.8457967842578014,
'k': -3.9048726800430713,
'4': -3.9411171656325226,
'5': -3.9708339604329925,
'g': -3.961715896933319,
'9': -4.019842096462643,
'6': -4.041864072829501,
'8': -4.096998079687665,
'7': -4.122126943234552,
'y': -4.1666976658279635,
'f': -4.351040269361279,
'w': -4.360690517108493,
'j': -4.741006747760368,
'v': -4.759276833451455,
'z': -5.036594538526155,
'x': -5.137009730369897,
'q': -5.624531280146579
}
ENGLISH_PRIOR = math.log(4 / 5)
class PostFilter:
"""
General filter for SE posts
"""
def __init__(self, all_sites=True, sites=None, max_rep=1, max_score=0, question=True, answer=True):
self.all_sites = all_sites
self.sites = set(sites) if sites is not None else set()
self.max_rep = max_rep
self.max_score = max_score
self.question = question
self.answer = answer
def match(self, post):
"""
See if a post matches this filter
"""
if (post.is_answer and not self.answer) or (not post.is_answer and not self.question):
# Wrong post type
return False
elif self.all_sites == (post.post_site in self.sites):
# Post is on wrong site
return False
elif (post.owner_rep > self.max_rep) or (post.post_score > self.max_score):
# High score or high rep
return False
else:
return True
class Rule:
"""
A single spam-checking rule
"""
default_filter = PostFilter()
def __init__(self, item, reason, title=True, body=True, body_summary=True, username=True, filter=None,
stripcodeblocks=False, whole_post=False):
self.regex = None
self.func = None
if isinstance(item, (str, URL_REGEX.__class__)):
self.regex = item
else:
self.func = item
self.reason = reason
self.title = title
self.body = body
self.body_summary = body_summary
self.username = username
self.filter = filter or Rule.default_filter
self.stripcodeblocks = stripcodeblocks
self.whole_post = whole_post
def match(self, post):
"""
Run this rule against a post. Returns a list of 3 tuples, each in (match, reason, why) format
"""
if not self.filter.match(post):
# Post not matching the filter
return [(False, "", "")] * 3
body_to_check = post.body.replace("&nsbp;", "").replace("\xAD", "") \
.replace("\u200B", "").replace("\u200C", "")
body_name = "body" if not post.is_answer else "answer"
reason_title = self.reason.replace("{}", "title")
reason_username = self.reason.replace("{}", "username")
reason_body = self.reason.replace("{}", body_name)
if self.stripcodeblocks:
# use a placeholder to avoid triggering "linked punctuation" on code-only links
body_to_check = regex.sub("(?s)<pre>.*?</pre>", "\nstripped pre\n", body_to_check)
body_to_check = regex.sub("(?s)<code>.*?</code>", "\nstripped code\n", body_to_check)
if self.reason == 'phone number detected in {}':
body_to_check = regex.sub("<(?:a|img)[^>]+>", "", body_to_check)
matched_title, matched_body, matched_username = False, False, False
result_title, result_username, result_body = None, None, None
if self.func: # Functional check takes precedence over regex check
if self.whole_post:
matched_title, matched_username, matched_body, why_text = self.func(post)
result_title = (matched_title, reason_title,
reason_title.capitalize() + " - " + why_text)
result_username = (matched_username, reason_username,
reason_username.capitalize() + " - " + why_text)
result_body = (matched_body, reason_body,
reason_body.capitalize() + " - " + why_text)
else:
if self.title and not post.is_answer:
matched_title, why_text = self.func(post.title, post.post_site)
result_title = (matched_title, reason_title,
reason_title.capitalize() + " - " + why_text)
else:
result_title = (False, "", "")
if self.username:
matched_username, why_text = self.func(post.user_name, post.post_site)
result_username = (matched_username, reason_username,
reason_username.capitalize() + " - " + why_text)
else:
result_username = (False, "", "")
if self.body and not post.body_is_summary:
matched_body, why_text = self.func(body_to_check, post.post_site)
result_body = (matched_body, reason_body,
reason_body.capitalize() + " - " + why_text)
elif self.body_summary and post.body_is_summary:
matched_body, useless = self.func(body_to_check, post.post_site)
result_body = (matched_body, "", "")
else:
result_body = (False, "", "")
elif self.regex:
compiled_regex = regex.compile(self.regex, regex.UNICODE, city=city_list)
if self.title and not post.is_answer:
matches = list(compiled_regex.finditer(post.title))
result_title = (bool(matches), reason_title,
reason_title.capitalize() + " - " + FindSpam.match_infos(matches))
else:
result_title = (False, "", "")
if self.username:
matches = list(compiled_regex.finditer(post.user_name))
result_username = (bool(matches), reason_username,
reason_username.capitalize() + " - " + FindSpam.match_infos(matches))
else:
result_username = (False, "", "")
if (self.body and not post.body_is_summary) \
or (self.body_summary and post.body_is_summary):
matches = list(compiled_regex.finditer(body_to_check))
result_body = (bool(matches), reason_body,
reason_body.capitalize() + " - " + FindSpam.match_infos(matches))
else:
result_body = (False, "", "")
else:
raise TypeError("A rule must have either 'func' or 'regex' valid!")
# "result" format: tuple((title_spam, reason, why), (username_spam, reason, why), (body_spam, reason, why))
return result_title, result_username, result_body
def __call__(self, *args, **kwargs):
# Preserve the functionality of a function
if self.func:
return self.func(*args, **kwargs)
raise TypeError("This rule has no function set, can't call")
class FindSpam:
rules = []
# supplied at the bottom of this file
rule_bad_keywords = None
rule_watched_keywords = None
rule_blacklisted_websites = None
rule_blacklisted_usernames = None
@classmethod
def reload_blacklists(cls):
global bad_keywords_nwb
blacklists.load_blacklists()
# See PR 2322 for the reason of (?:^|\b) and (?:\b|$)
# (?w:\b) is also useful
cls.rule_bad_keywords.regex = r"(?is)(?:^|\b|(?w:\b))(?:{})(?:\b|(?w:\b)|$)|{}".format(
"|".join(GlobalVars.bad_keywords), "|".join(bad_keywords_nwb))
cls.rule_watched_keywords.regex = r'(?is)(?:^|\b|(?w:\b))(?:{})(?:\b|(?w:\b)|$)'.format(
"|".join(GlobalVars.watched_keywords.keys()))
cls.rule_blacklisted_websites.regex = r"(?i)({})".format(
"|".join(GlobalVars.blacklisted_websites))
cls.rule_blacklisted_usernames.regex = r"(?i)({})".format(
"|".join(GlobalVars.blacklisted_usernames))
GlobalVars.blacklisted_numbers, GlobalVars.blacklisted_numbers_normalized = \
process_numlist(GlobalVars.blacklisted_numbers)
GlobalVars.watched_numbers, GlobalVars.watched_numbers_normalized = \
process_numlist(GlobalVars.watched_numbers)
log('debug', "Global blacklists loaded")
@staticmethod
def test_post(post):
result = []
why_title, why_username, why_body = [], [], []
for rule in FindSpam.rules:
title, username, body = rule.match(post)
if title[0]:
result.append(title[1])
why_title.append(title[2])
if username[0]:
result.append(username[1])
why_username.append(username[2])
if body[0]:
result.append(body[1])
why_body.append(body[2])
result = list(set(result))
result.sort()
why = "\n".join(sorted(why_title + why_username + why_body)).strip()
return result, why
@staticmethod
def match_info(match):
start, end = match.span()
group = match.group().replace("\n", "")
return "Position {}-{}: {}".format(start + 1, end, group)
@staticmethod
def match_infos(matches):
spans = {}
for match in matches:
group = match.group().strip().replace("\n", "")
if group not in spans:
spans[group] = [match.span()]
else:
spans[group].append(match.span())
infos = [(sorted(spans[word]), word) for word in spans]
infos.sort(key=lambda info: info[0]) # Sort by positions of appearances
return ", ".join([
"Position{} {}: {}".format(
"s" if len(span) > 1 else "",
", ".join(
["{}-{}".format(a, b) for a, b in span]
if len(span) < 14 else
["{}-{}".format(a, b) for a, b in span[:12]] + ["+{} more".format(len(span) - 12)]
),
word
)
for span, word in infos])
########################################################################################################################
# The Creator of all the spam check rules
# Do NOT touch the default values unless you want to break things
# what if a function does more than one job?
def create_rule(reason, regex=None, func=None, *, all=True, sites=[],
title=True, body=True, body_summary=False, username=False,
max_score=0, max_rep=1, question=True, answer=True, stripcodeblocks=False,
whole_post=False, # For some functions
disabled=False): # yeah, disabled=True is intuitive
if not isinstance(reason, str):
raise ValueError("reason must be a string")
if not (body or body_summary or username): # title-only
answer = False # answers have no titles, this saves some loops
post_filter = PostFilter(all_sites=all, sites=sites, max_score=max_score, max_rep=max_rep,
question=question, answer=answer)
if regex is not None:
# Standalone mode
rule = Rule(regex, reason=reason, filter=post_filter,
title=title, body=body, body_summary=body_summary, username=username,
stripcodeblocks=stripcodeblocks)
if not disabled:
FindSpam.rules.append(rule)
return rule
else:
# Decorator-generator mode
def decorator(func):
if isinstance(func, Rule):
func = func.func # Extract the real function from the created rule to allow multi-creation
try:
func.__call__
except AttributeError:
raise ValueError("This rule does not contain a function, can't recreate") from None
rule = Rule(func, reason=reason, filter=post_filter, whole_post=whole_post,
title=title, body=body, body_summary=body_summary, username=username,
stripcodeblocks=stripcodeblocks)
if not disabled:
FindSpam.rules.append(rule)
return rule
if func is not None: # Function is supplied, no need to decorate
return decorator(func)
else: # real decorator mode
return decorator
def is_whitelisted_website(url):
# Imported from method link_at_end
return bool(WHITELISTED_WEBSITES_REGEX.search(url)) or metasmoke_cache.is_website_whitelisted(url)
def levenshtein(s1, s2):
if len(s1) < len(s2):
return levenshtein(s2, s1)
if len(s2) == 0:
return len(s1)
previous_row = range(len(s2) + 1)
for i, c1 in enumerate(s1):
current_row = [i + 1]
for j, c2 in enumerate(s2):
insertions = previous_row[j + 1] + 1
deletions = current_row[j] + 1
substitutions = previous_row[j] + (c1 != c2)
current_row.append(min(insertions, deletions, substitutions))
previous_row = current_row
return previous_row[-1]
def contains_tld(s):
global TLD_CACHE
# Hackity hack.
if len(TLD_CACHE) == 0:
with open(path.join(tld.defaults.NAMES_LOCAL_PATH_PARENT, tld.defaults.NAMES_LOCAL_PATH),
'r', encoding="utf-8") as f:
TLD_CACHE = [x.rstrip('\n') for x in f.readlines() if x.rstrip('\n') and
not x.strip().startswith('//')]
return any(('.' + x) in s for x in TLD_CACHE)
@create_rule("misleading link", title=False, max_rep=10, max_score=1, stripcodeblocks=True)
def misleading_link(s, site):
link_regex = r"<a href=\"([^\"]+)\"[^>]*>([^<]+)<\/a>"
compiled = regex.compile(link_regex)
search = compiled.search(s)
if search is None:
return False, ''
href, text = search[1], search[2]
try:
parsed_href = tld.get_tld(href, as_object=True)
if parsed_href.fld in SE_SITES_DOMAINS:
log('debug', "{}: SE domain".format(parsed_href.fld))
return False, ''
log('debug', "{}: not an SE domain".format(parsed_href.fld))
if contains_tld(text) and ' ' not in text:
parsed_text = tld.get_tld(text, fix_protocol=True, as_object=True)
else:
raise tld.exceptions.TldBadUrl('Link text is not a URL')
except (tld.exceptions.TldDomainNotFound, tld.exceptions.TldBadUrl, ValueError) as err:
return False, ''
if site == 'stackoverflow.com' and parsed_text.fld.split('.')[-1] in SAFE_EXTENSIONS:
return False, ''
if levenshtein(parsed_href.domain, parsed_text.domain) <= LEVEN_DOMAIN_DISTANCE: # Preempt
return False, ''
try:
href_domain = unquote_plus(parsed_href.domain.encode("ascii").decode("idna"))
except ValueError:
href_domain = parsed_href.domain
try:
text_domain = unquote_plus(parsed_text.domain.encode("ascii").decode("idna")) # people do post this, sad
except ValueError:
text_domain = parsed_text.domain
if levenshtein(href_domain, text_domain) > LEVEN_DOMAIN_DISTANCE:
return True, 'Domain {} indicated by possible misleading text {}.'.format(
parsed_href.fld, parsed_text.fld
)
else:
return False, ''
# noinspection PyUnusedLocal,PyMissingTypeHints,PyTypeChecker
@create_rule("repeating words in {}", max_rep=11, stripcodeblocks=True)
def has_repeating_words(s, site):
# RegEx DoS warning!!!
matcher = regex.compile(r"\b(?P<words>(?P<word>[a-z]+))(?:[][\s.,;!/\()+_-]+(?P<words>(?P=word))){4,}\b",
flags=regex.I | regex.S | regex.V0)
for match in matcher.finditer(s):
words = match.captures("words")
word = match.group("word")
if len(words) >= 5 and len(word) * len(words) >= 0.18 * len(s):
return True, "{}*{}".format(repr(word), len(words))
return False, ""
# noinspection PyUnusedLocal,PyMissingTypeHints
@create_rule("few unique characters in {}", title=False, max_rep=10000, max_score=10000)
def has_few_characters(s, site):
s = regex.sub("</?(?:p|strong|em)>", "", s).rstrip() # remove HTML paragraph tags from posts
uniques = len(set(s) - {"\n", "\t"})
length = len(s)
thresholds = [ # LBound, UBound, MaxUnique
(30, 36, 6), (36, 42, 7), (42, 48, 8), (48, 54, 9), (54, 60, 10),
(60, 70, 11), (70, 80, 12), (80, 90, 13), (90, 100, 14), (100, 2**30, 15),
]
if any([t[0] <= length < t[1] and uniques <= t[2] for t in thresholds]):
if uniques >= 5 and site == "math.stackexchange.com":
# Special case for Math.SE: Uniques case may trigger false-positives.
return False, ""
return True, "Contains {} unique character{}".format(uniques, "s" if uniques >= 2 else "")
return False, ""
# noinspection PyUnusedLocal,PyMissingTypeHints
@create_rule("repeating characters in {}", stripcodeblocks=True, max_rep=10000, max_score=10000)
def has_repeating_characters(s, site):
s = s.strip().replace("\u200B", "").replace("\u200C", "") # Strip leading and trailing spaces
if "\n\n" in s or "<code>" in s or "<pre>" in s:
return False, ""
s = regex.sub(URL_REGEX, "", s) # Strip URLs for this check
if not s:
return False, ""
# matches = regex.compile(r"([^\s_.,?!=~*/0-9-])(\1{9,})", regex.UNICODE).findall(s)
matches = regex.compile(r"([^\s\d_.])(\1{9,})", regex.UNICODE).findall(s)
match = "".join(["".join(match) for match in matches])
if len(match) / len(s) >= REPEATED_CHARACTER_RATIO: # Repeating characters make up >= 20 percent
return True, "{}".format(", ".join(
["{}*{}".format(repr(match[0]), len(''.join(match))) for match in matches]))
return False, ""
# noinspection PyUnusedLocal,PyMissingTypeHints
@create_rule("link at end of {}", title=False, all=False, sites=[
"superuser.com", "askubuntu.com", "drupal.stackexchange.com", "meta.stackexchange.com",
"security.stackexchange.com", "patents.stackexchange.com", "money.stackexchange.com",
"gaming.stackexchange.com", "arduino.stackexchange.com", "workplace.stackexchange.com"])
def link_at_end(s, site): # link at end of question, on selected sites
s = regex.sub("</?(?:strong|em|p)>", "", s)
match = regex.compile(r"(?i)https?://(?:[.A-Za-z0-9-]*/?[.A-Za-z0-9-]*/?|plus\.google\.com/"
r"[\w/]*|www\.pinterest\.com/pin/[\d/]*)(?=</a>\s*$)").search(s)
if match and not is_whitelisted_website(match.group(0)):
return True, u"Link at end: {}".format(match.group(0))
return False, ""
# noinspection PyUnusedLocal,PyMissingTypeHints,PyTypeChecker
@create_rule("non-English link in {}", title=False, question=False, stripcodeblocks=True, sites=[
"pt.stackoverflow.com", "es.stackoverflow.com", "ja.stackoverflow.com", "ru.stackoverflow.com",
"rus.stackexchange.com", "islam.stackexchange.com", "japanese.stackexchange.com", "hinduism.stackexchange.com",
"judaism.stackexchange.com", "buddhism.stackexchange.com", "chinese.stackexchange.com",
"russian.stackexchange.com", "french.stackexchange.com", "portuguese.stackexchange.com",
"spanish.stackexchange.com", "codegolf.stackexchange.com", "korean.stackexchange.com",
"esperanto.stackexchange.com", "ukrainian.stackexchange.com"])
def non_english_link(s, site): # non-english link in short answer
if len(s) < 600:
links = regex.compile(r'nofollow(?: noreferrer)?">([^<]*)(?=</a>)', regex.UNICODE).findall(s)
for link_text in links:
word_chars = regex.sub(r"(?u)\W", "", link_text)
non_latin_chars = regex.sub(r"\w", "", word_chars)
if len(word_chars) >= 1 and ((len(word_chars) <= 20 and len(non_latin_chars) >= 1) or
(len(non_latin_chars) >= 0.05 * len(word_chars))):
return True, u"Non-English link text: *{}*".format(link_text)
return False, ""
# noinspection PyUnusedLocal,PyMissingTypeHints,PyTypeChecker
@create_rule("mostly non-Latin {}", stripcodeblocks=True, sites=[
"stackoverflow.com", "ja.stackoverflow.com", "pt.stackoverflow.com", "es.stackoverflow.com",
"islam.stackexchange.com", "japanese.stackexchange.com", "anime.stackexchange.com",
"hinduism.stackexchange.com", "judaism.stackexchange.com", "buddhism.stackexchange.com",
"chinese.stackexchange.com", "french.stackexchange.com", "spanish.stackexchange.com",
"portuguese.stackexchange.com", "codegolf.stackexchange.com", "korean.stackexchange.com",
"ukrainian.stackexchange.com"], body_summary=True)
@create_rule("mostly non-Latin {}", all=False, sites=["stackoverflow.com"],
stripcodeblocks=True, body_summary=True, question=False)
def mostly_non_latin(s, site): # majority of post is in non-Latin, non-Cyrillic characters
word_chars = regex.sub(r'(?u)[\W0-9]|http\S*', "", s)
non_latin_chars = regex.sub(r"(?u)\p{script=Latin}|\p{script=Cyrillic}", "", word_chars)
if len(non_latin_chars) > 0.4 * len(word_chars):
return True, "Text contains {} non-Latin characters out of {}".format(len(non_latin_chars), len(word_chars))
return False, ""
# noinspection PyUnusedLocal,PyMissingTypeHints
@create_rule("phone number detected in {}", body=False, sites=[
"patents.stackexchange.com", "math.stackexchange.com", "mathoverflow.net"])
def has_phone_number(s, site):
if regex.compile(r"(?i)\b(address(es)?|run[- ]?time|error|value|server|hostname|timestamp|warning|code|"
r"(sp)?exception|version|chrome|1234567)\b", regex.UNICODE).search(s):
return False, "" # not a phone number
s = regex.sub("[^A-Za-z0-9\\s\"',|]", "", s) # deobfuscate
s = regex.sub("[Oo]", "0", s)
s = regex.sub("[Ss]", "5", s)
s = regex.sub("[Iil|]", "1", s)
matched = regex.compile(r"(?<!\d)(?:\d{2}\s?\d{8,11}|\d\s{0,2}\d{3}\s{0,2}\d{3}\s{0,2}\d{4}|8\d{2}"
r"\s{0,2}\d{3}\s{0,2}\d{4})(?!\d)", regex.UNICODE).findall(s)
test_formats = ["IN", "US", "NG", None] # ^ don't match parts of too long strings of digits
for phone_number in matched:
if regex.compile(r"^21474(672[56]|8364)|^192168|^3221225").search(phone_number):
return False, "" # error code or limit of int size, or 192.168 IP, or 0xC000000_ error code
for testf in test_formats:
try:
z = phonenumbers.parse(phone_number, testf)
if phonenumbers.is_possible_number(z) and phonenumbers.is_valid_number(z):
log('debug', "Possible {}, Valid {}, Explain: {}".format(phonenumbers.is_possible_number(z),
phonenumbers.is_valid_number(z), z))
return True, u"Phone number: {}".format(phone_number)
except phonenumbers.phonenumberutil.NumberParseException:
pass
return False, ""
# noinspection PyMissingTypeHints
def check_numbers(s, numlist, numlist_normalized=None):
"""
Extract sequences of possible phone numbers. Check extracted numbers
against verbatim match (identical to item in list) or normalized match
(digits are identical, but spacing or punctuation contains differences).
"""
numlist_normalized = numlist_normalized or set()
matches = []
for number_candidate in NUMBER_REGEX.findall(s):
if number_candidate in numlist:
matches.append('{0} found verbatim'.format(number_candidate))
continue
# else
normalized_candidate = regex.sub(r"[^\d]", "", number_candidate)
if normalized_candidate in numlist_normalized:
matches.append('{0} found normalized'.format(normalized_candidate))
if matches:
return True, '; '.join(matches)
else:
return False, ''
def process_numlist(numlist):
processed = set(numlist) # Sets are faster than Hong Kong journalists!
normalized = {regex.sub(r"\D", "", entry) for entry in numlist}
return processed, normalized
@create_rule("bad phone number in {}", body_summary=True, max_rep=5, max_score=1, stripcodeblocks=True)
def check_blacklisted_numbers(s, site):
return check_numbers(s,
GlobalVars.blacklisted_numbers,
GlobalVars.blacklisted_numbers_normalized)
@create_rule("potentially bad keyword in {}", body_summary=True, max_rep=5, max_score=1, stripcodeblocks=True)
def check_watched_numbers(s, site):
return check_numbers(s,
GlobalVars.watched_numbers,
GlobalVars.watched_numbers_normalized)
# noinspection PyUnusedLocal,PyMissingTypeHints
@create_rule("bad keyword in {}")
def has_customer_service(s, site): # flexible detection of customer service
s = s[0:300].lower() # if applied to body, the beginning should be enough: otherwise many false positives
s = regex.sub(r"[^A-Za-z0-9\s]", "", s) # deobfuscate
phrase = regex.compile(r"(tech(nical)? support)|((support|service|contact|help(line)?) (telephone|phone|"
r"number))").search(s)
if phrase and site in ["askubuntu.com", "webapps.stackexchange.com", "webmasters.stackexchange.com"]:
return True, u"Key phrase: *{}*".format(phrase.group(0))
business = regex.compile(
r"(?i)\b(airlines?|apple|AVG|BT|netflix|dell|Delta|epson|facebook|gmail|google|hotmail|hp|"
r"lexmark|mcafee|microsoft|norton|out[l1]ook|quickbooks|sage|windows?|yahoo)\b").search(s)
digits = len(regex.compile(r"\d").findall(s))
if business and digits >= 5:
keywords = regex.compile(r"(?i)\b(customer|help|care|helpline|reservation|phone|recovery|service|support|"
r"contact|tech|technical|telephone|number)\b").findall(s)
if len(set(keywords)) >= 2:
matches = ", ".join(["".join(match) for match in keywords])
return True, u"Scam aimed at *{}* customers. Keywords: *{}*".format(business.group(0), matches)
return False, ""
# Bad health-related keywords in titles, health sites are exempt
@create_rule("bad keyword in {}", body=False, all=False, sites=[
"stackoverflow.com", "superuser.com", "askubuntu.com", "drupal.stackexchange.com",
"meta.stackexchange.com", "security.stackexchange.com", "webapps.stackexchange.com",
"apple.stackexchange.com", "graphicdesign.stackexchange.com", "workplace.stackexchange.com",
"patents.stackexchange.com", "money.stackexchange.com", "gaming.stackexchange.com", "arduino.stackexchange.com"])
def has_health(s, site): # flexible detection of health spam in titles
s = s[0:200] # if applied to body, the beginning should be enough: otherwise many false positives
capitalized = len(regex.compile(r"\b[A-Z][a-z]").findall(s)) >= 5 # words beginning with uppercase letter
organ = regex.compile(r"(?i)\b(colon|skin|muscle|bicep|fac(e|ial)|eye|brain|IQ|mind|head|hair|peni(s|le)|"
r"breast|body|joint|belly|digest\w*)s?\b").search(s)
condition = regex.compile(r"(?i)\b(weight|constipat(ed|ion)|dysfunction|swollen|sensitive|wrinkle|aging|"
r"suffer|acne|pimple|dry|clog(ged)?|inflam(ed|mation)|fat|age|pound)s?\b").search(s)
goal = regex.compile(r"(?i)\b(supple|build|los[es]|power|burn|erection|tone(d)|rip(ped)?|bulk|get rid|mood)s?\b|"
r"\b(diminish|look|reduc|beaut|renew|young|youth|lift|eliminat|enhance|energ|shred|"
r"health(?!kit)|improve|enlarge|remov|vital|slim|lean|boost|str[oe]ng)").search(s)
remedy = regex.compile(r"(?i)\b(remed(y|ie)|serum|cleans?(e|er|ing)|care|(pro)?biotic|herbal|lotion|cream|"
r"gel|cure|drug|formula|recipe|regimen|solution|therapy|hydration|soap|treatment|supplement|"
r"diet|moist\w*|injection|potion|ingredient|aid|exercise|eat(ing)?)s?\b").search(s)
boast = regex.compile(r"(?i)\b(most|best|simple|top|pro|real|mirac(le|ulous)|secrets?|organic|natural|perfect|"
r"ideal|fantastic|incredible|ultimate|important|reliable|critical|amazing|fast|good)\b|"
r"\b(super|hyper|advantag|benefi|effect|great|valu|eas[iy])").search(s)
other = regex.compile(r"(?i)\b(product|thing|item|review|advi[cs]e|myth|make use|your?|really|work|tip|shop|"
r"store|method|expert|instant|buy|fact|consum(e|ption)|baby|male|female|men|women|grow|"
r"idea|suggest\w*|issue)s?\b").search(s)
score = 4 * bool(organ) + 2 * bool(condition) + 2 * bool(goal) + 2 * bool(remedy) + bool(boast) + \
bool(other) + capitalized
if score >= 8:
match_objects = [organ, condition, goal, remedy, boast, other]
words = [match.group(0) for match in match_objects if match]
return True, u"Health-themed spam (score {}). Keywords: *{}*".format(score, ", ".join(words).lower())
return False, ""
# Pattern-matching product name: three keywords in a row at least once, or two in a row at least twice
@create_rule("pattern-matching product name in {}", body_summary=True, stripcodeblocks=True, answer=False,
max_rep=4, max_score=1)
def pattern_product_name(s, site):
required_keywords = [
"Testo(?:sterone)?s?", "Derma?(?:pholia)?", "Garcinia", "Cambogia", "Forskolin", "Diet", "Slim", "Serum",
"Junivive", "Gain", "Allure", "Nuvella", "Blast", "Burn", "Shark", "Peni(?:s|le)", "Pills?", "CBD",
"Elite", "Exceptional", "Enhance(?:ment)?", "Nitro", "Suppl[ei]ments?",
"Skin", "Muscle", "Therm[ao]", "Neuro", "Luma", "Rapid", "Tone", "Keto", "Cream",
"(?:Anti)?[ -]?Aging", "Trim", "Male", r"Weight\W?(?:Loss|Reduction)", "Radiant(?:ly)?",
"Boost(?:er|ing)?s?", "Youth", "Monster", "Enlarge(?:ment)", "Obat", "Nutr[ai]",
]
keywords = required_keywords + [
r"(?<=(?:keto\w*|diet)\W*)\w+(?=\W*(?:keto\w*|diet))", # Tricky approach for "keto whatever diet"
# r"\w+(?=-)(?=(?:\W*(?:keto\w*|diet)){2,})", # Too dangerous
"Deep", "Pro", "Advanced?", "Divine", "Royale?", "Angele*", "Trinity", "Andro", "Force", "Healthy?",
"Sea", "Ascend", "Premi(?:um|er)", "Master", "Ultra", "Vital", "Perfect", "Bio", "Natural?", "Oil",
"E?xtreme", "Fit", "Thirsty?", "Grow", "Complete", "Reviews?", "Bloom(?:ing)?", "BHB", "Pures?t?", "Quick",
"Titan", "Hyper", "X[LRT]", "[R]X", "Supply", "Power", "Aged?", "Ultimate", "Surge", "(?<!e)Xtra",
"Brain", "Fuel", "Melt", "Fire", "Tank", "Life",
]
conjunctions = [ # lol, for "keto melt and trim"
"And", "For", "With", "In", "This", "To", "About", "Or", "Where", "What", "Is", "A",
]
if site not in {"math.stackexchange.com", "mathoverflow.net"}:
keywords.extend([r"X\d?", "Alpha", "Plus", "Prime", "Formula", "Max+"])
keywords = regex.compile(r"(?i)\b(?P<x>{0})(?:[ -]*(?:(?:{1})[ -]*)*(?P<x>{0}))+\b".format(
"|".join(keywords), "|".join(conjunctions)))
required = regex.compile(r"(?i){}".format("|".join(required_keywords)))
match_items = list(keywords.finditer(s))
matches = [m.captures("x") for m in match_items if required.search(m.group(0))]
# Total "unique words in each match"
total_words = sum([n for n in [len(set([regex.sub(r"\d", "", w) for w in m])) for m in matches] if n >= 2])
if total_words >= 3:
return True, FindSpam.match_infos(match_items)
return False, ""
@create_rule("bad keyword with email in {}", stripcodeblocks=True)
def keyword_email(s, site): # a keyword and an email in the same post
if regex.compile("<pre>|<code>").search(s) and site == "stackoverflow.com": # Avoid false positives on SO
return False, ""
keyword = regex.compile(r"(?i)(\b(?:training|we (will )?(offer|develop|provide)|sell|invest(or|ing|ment)|credit|"
r"money|quality|legit|interest(ed)?|guarantee|rent|crack|opportunity|fundraising|campaign|"
r"career|employment|candidate|loan|lover|husband|wife|marriage|illuminati|brotherhood|"
r"(join|contact) (me|us|him)|reach (us|him)|spell(caster)?|doctor|cancer|krebs|"
r"(cheat|hack)(er|ing)?|spying|passport|seaman|scam|pics|vampire|bless(ed)?|atm|miracle|"
r"cure|testimony|kidney|hospital|wetting)s?\b|(?<=\s)Dr\.?(?=\s)|\$ ?[0-9,.]{4}|@qq\.com|"
r"\b(?:герпес|муж|жена|доктор|болезн))").findall(s)
keyword = [t[0] for t in keyword]
email = regex.compile(r"(?<![=#/])\b[A-z0-9_.%+-]+\b(?:@|\s*\(?at\)?\s*)\b(?!(example|domain|site|foo|\dx)"
r"(?:\.|\s*\(?dot\)?\s*)[A-z]{2,4})\b(?:[A-z0-9_.%+-]|\s*\(?dot\)?\s*)+\b"
r"(?:\.|\s*\(?dot\)?\s*)[A-z]{2,4}\b").search(s)
if keyword and email:
return True, u"Keyword *{}* with email *{}*".format(", ".join(keyword), email.group(0))
obfuscated_email = regex.compile(
r"(?<![=#/])\b[A-z0-9_.%+-]+ *(?:@|\W*at\W*) *(g *mail|yahoo) *(?:\.|\W*dot\W*) *com\b").search(s)
if obfuscated_email and not email:
return True, u"Obfuscated email {}".format(obfuscated_email.group(0))
return False, ""
@create_rule("pattern-matching email in {}", stripcodeblocks=True)
def pattern_email(s, site):
pattern = regex.compile(r"(?i)(?<![=#/])\b(dr|[A-z0-9_.%+-]*"
r"(loan|hack|financ|fund|spell|temple|herbal|spiritual|atm|heal|priest|classes|"
r"investment|illuminati|vampire?))[A-z0-9_.%+-]*"
r"@(?!(example|domain|site|foo|\dx)\.[A-z]{2,4})[A-z0-9_.%+-]+\.[A-z]{2,4}\b"
).finditer(s)
pattern = list(pattern)
if pattern:
return True, FindSpam.match_infos(pattern)
return False, ""
@create_rule("bad keyword with a link in {}", title=False, question=False)
def keyword_link(s, site): # thanking keyword and a link in the same short answer
if len(s) > 400:
return False, ""
link = regex.compile(r'(?i)<a href="https?://\S+').search(s)
if not link or is_whitelisted_website(link.group(0)):
return False, ""
praise = regex.compile(r"(?i)\b(nice|good|interesting|helpful|great|amazing) (article|blog|post|information)\b|"
r"very useful").search(s)
thanks = regex.compile(r"(?i)\b(appreciate|than(k|ks|x))\b").search(s)
keyword = regex.compile(r"(?i)\b(I really appreciate|many thanks|thanks a lot|thank you (very|for)|"
r"than(ks|x) for (sharing|this|your)|dear forum members|(very (informative|useful)|"
r"stumbled upon (your|this)|wonderful|visit my) (blog|site|website))\b").search(s)
if link and keyword:
return True, u"Keyword *{}* with link {}".format(keyword.group(0), link.group(0))
if link and thanks and praise:
return True, u"Keywords *{}*, *{}* with link {}".format(thanks.group(0), praise.group(0), link.group(0))
return False, ""
@create_rule("bad keyword in link text in {}", title=False, stripcodeblocks=True)
def bad_link_text(s, site): # suspicious text of a hyperlink
s = regex.sub("</?(?:strong|em)>", "", s) # remove font tags
keywords = regex.compile(
r"(?isu)"
r"\b(buy|cheap) |live[ -]?stream|"
r"\bmake (money|\$)|"
r"\b(porno?|(whole)?sale|coins|luxury|coupons?|essays?|in \L<city>)\b|"
r"\b\L<city>(?:\b.{1,20}\b)?(service|escort|call girls?)|"
r"\b(?:customer|recovery|technical|recovery)? ?(?:customer|support|service|repair|contact) "
r"(?:phone|hotline|helpline)? ?numbers?\b|"
r"(best|make|full|hd|software|cell|data|media)[\w ]{1,20}"
r"" r"(online|service|company|agency|repair|recovery|school|university)|"
r"\b(writing (service|help)|essay (writing|tips))", city=city_list)
links = regex.compile(r'nofollow(?: noreferrer)?">([^<]*)(?=</a>)', regex.UNICODE).findall(s)
business = regex.compile(
r"(?i)(^| )(airlines?|apple|AVG|BT|netflix|dell|Delta|epson|facebook|gmail|google|hotmail|hp|"
r"lexmark|mcafee|microsoft|norton|out[l1]ook|quickbooks|sage|windows?|yahoo)($| )")
# FIXME/TODO: Remove "help" once WebApps has stopped being hit with gmail help spam. (added: Art, 2018-10-17)
support = regex.compile(r"(?i)(^| )(customer|care|helpline|reservation|phone|recovery|service|support|contact|"
r"help|tech|technical|telephone|number)($| )")
for link_text in links:
keywords_match = keywords.search(link_text)
if keywords_match:
return True, u"Bad keyword *{}* in link text".format(keywords_match.group(0).strip())
business_match = business.search(link_text)
support_match = support.search(link_text)
if business_match and support_match:
return True, u"Bad keywords *{}*, *{}* in link text".format(business_match.group(0).strip(),
support_match.group(0).strip())
return False, ""
@create_rule("bad pattern in URL {}", title=False, body_summary=True, stripcodeblocks=True)
def bad_pattern_in_url(s, site):
patterns = [
r'[^"]*-reviews?(?:-(?:canada|(?:and|or)-scam))?/?',
r'[^"]*-support/?',
]
matches = regex.compile(
r'<a href="(?P<frag>{0})"|<a href="[^"]*"(?:\s+"[^"]*")*>(?P<frag>{0})</a>'.format(
'|'.join(patterns)), regex.UNICODE).findall(s)
matches = [x for x in matches if not regex.match(
r'^https?://{0}'.format(SE_SITES_RE), x[0])]
if matches:
return True, u"Bad fragment in link {}".format(
", ".join(["".join(match) for match in matches]))
else:
return False, ""
def purge_cache(cachevar, limit):
'''
Trim down cache variable to the specified number of newest entries.
'''
oldest = sorted(cachevar, key=lambda k: cachevar[k]['timestamp'])[0:limit + 1]
remaining = oldest.pop()
now = datetime.now()
log('debug', 'purge_cache({0}): age of oldest entry is {1}'.format(
limit, now - cachevar[oldest[0]]['timestamp']))
log('debug', 'purge_cache({0}): oldest remaining entry is {1}'.format(
limit, now - cachevar[remaining]['timestamp']))
for old in oldest:
# Guard against KeyError; race condition?
if old in cachevar:
del cachevar[old]
def dns_query(label, qtype):
global DNS_CACHE
if (label, qtype) in DNS_CACHE:
log('debug', 'dns_query: returning cached {0} value for {1}'.format(
qtype, label))
return DNS_CACHE[(label, qtype)]['result']
try:
starttime = datetime.now()
answer = dns.resolver.query(label, qtype)
except dns.exception.DNSException as exc:
if str(exc).startswith('None of DNS query names exist:'):
log('debug', 'DNS label {0} not found; skipping'.format(label))
else:
endtime = datetime.now()
log('warning', 'DNS error {0} (duration: {1})'.format(
exc, endtime - starttime))
return None
endtime = datetime.now()
log('debug', '{0} query duration: {1}'.format(qtype, endtime - starttime))
DNS_CACHE[(label, qtype)] = {'result': answer, 'timestamp': endtime}
# Periodic amortized cache cleanup: clean out oldest 1000 entries
if len(DNS_CACHE.keys()) >= 1500:
log('debug', 'Initiating cleanup of DNS_CACHE')
purge_cache(DNS_CACHE, 1000)
log('debug', 'DNS cleanup took an additional {0} seconds'.format(
datetime.now() - endtime))
return answer
def asn_query(ip):
'''
http://www.team-cymru.com/IP-ASN-mapping.html
'''
pi = list(reversed(ip.split('.')))
asn = dns_query('.'.join(pi + ['origin.asn.cymru.com.']), 'txt')
if asn is not None:
for txt in set([str(x) for x in asn]):
log('debug', '{0}: Raw ASN lookup result: {1}'.format(ip, txt))
if ' | ' in txt:
return txt.split(' | ')[0].strip('"')
return None
def ns_for_url_domain(s, site, nslist):
if "pytest" in sys.modules:
for nsentry in nslist:
if isinstance(nsentry, set):
for ns in nsentry:
assert ns.endswith('.'),\
"Missing final dot on NS entry {0}".format(ns)
else:
assert nsentry.endswith('.'),\
"Missing final dot on NS entry {0}".format(nsentry)
domains = []
for hostname in post_hosts(s, check_tld=True):
domains.append(get_domain(hostname, full=True))
for domain in set(domains):
ns = dns_query(domain, 'ns')
if ns is not None:
nameservers = set([server.target.to_text() for server in ns])
for ns_candidate in nslist:
if (type(ns_candidate) is set and nameservers == ns_candidate) \
or any(ns.endswith('.{0}'.format(ns_candidate))
for ns in nameservers):
return True, '{domain} NS suspicious {ns}'.format(
domain=domain, ns=','.join(nameservers))
return False, ""
@create_rule("potentially problematic NS configuration in {}", stripcodeblocks=True, body_summary=True)
def ns_is_host(s, site):
'''
Check if the host name in a link resolves to the same IP address
as the IP addresses of all its name servers.
'''
for hostname in post_hosts(s, check_tld=True):
host_ip = dns_query(hostname, 'a')
if host_ip is None: