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2010 User-Agent Blacklist

[ 2010 User-Agent Blacklist ] The 2010 User-Agent Blacklist blocks hundreds of bad bots while ensuring open-access for the major search engines: Google, Bing, Ask, Yahoo, et al. Blocking bad user-agents is an effective addition to any security strategy. It works like this: your site is getting hammered by rogue bots that waste valuable server resources and bandwidth. So you grab a copy of the 2010 UA Blacklist from Perishable Press, include it in your site’s root .htaccess file, and enjoy better security and performance. It’s that easy.

Update: Check out the new and improved 2013 User Agent Blacklist!

Proven Security

The 2010 UA Blacklist has been carefully constructed based on rigorous server-log analyses. Obsessive daily log monitoring reveals bad bots scanning for exploits, spamming resources, and wasting bandwidth. While analyzing malicious behavior, evil bots are identified and added to the UA Blacklist. Blocked user-agents are denied access to your site, increasing efficiency and providing safety for your visitors.

Better Performance, Better SEO

Search engines such as Google are placing more weight on speedy, fast-loading websites. If your site is plagued with resource-devouring, bandwidth-wasting bots, it’s performance is probably not as good as it should be. Even if your site looks fine on the surface, without proper protection bad bots can gobble your bandwidth and leech your server resources. A single malicious bot can make hundreds and thousands of requests in a very short period of time while scanning and probing for vulnerabilities. If Google visits while bad bots are hitting your site, your site’s SEO could suffer. Fortunately, the 2010 UA Blacklist protects your site against hundreds of nefarious bots, thereby fostering maximum performance for the search engines.

2010 User-Agent Blacklist

Here it is, presented as two sets of HTAccess directives:

RewriteCond %{HTTP_HOST} !^(127\.0\.0\.0|localhost) [NC]
RewriteCond %{HTTP_USER_AGENT} .*(Firs|exac|Cloak|Detect|uchoo|beaut|ASPSeek|swish|ICS\)|MSIE\ 6\.0\;\ Windows\ NT\;\ DigExt\)|pt\-BR\;\ rv\:1\.9\.0\.3\)\ Firefox\/3\.0|pt\-BR\;\ rv\:1\.9\.0\.18\)\ Firefox\/3\.0|\!susie|\$x0e|\%0a|\%0d|\@\$x|\_irc|\_works|\+select\+|\+union\+|\<\?|1\,\1\,1\,|3gse|4all|4anything|5\.1\;\ xv6875\)|59\.64\.153\.|85\.17\.|88\.0\.106\.|98|a\_browser|a1\ site|abac|abach|abby|aberja|abilon|abont|abot|accept|access|accoo|accoon|aceftp|acme|active|address|adopt|adress|advisor|agent|ahead|aihit|aipbot|alarm|albert|alek|alexa\ toolbar\;\ \(r1\ 1\.5\)|alltop|alma|alot|alpha|america\ online\ browser\ 1\.1|amfi|amfibi|anal|andit|anon|ansearch|answer|answerbus|answerchase|antivirx|apollo|appie|arach|archive|arian|aboutoil|asps|aster|atari|atlocal|atom|atrax|atrop|attrib|autoh|autohot|av\ fetch|avsearch|axod|axon|baboom|baby|back|baid|bali|bandit|barry|basichttp|batch|bdfetch|beat|become|bee|beij|betabot|biglotron|bilgi|bison|bitacle|bitly|blaiz|blitz|blogl|blogscope|blogzice|bloob|blow|bord|boi|bond|boris|bost|bot\.ara|botje|botw|bpimage|brand|brok|broth|browseabit|browsex|bruin|bsalsa|bsdseek|built|bulls|bumble|bunny|busca|busi|buy|bwh3|cafek|cafi|camel|cand|captu|casper|catch|ccbot|ccubee|cd34|ceg|cfnetwork|cgichk|cha0s|chang|chaos|char|char\(|chase\ x|check\_http|checker|checkonly|chek|chill|chttpclient|cipinet|cisco|cita|citeseer|clam|claria|claw|clush|coast|code\.com|cogent|coldfusion|coll|collect|comb|combine|commentreader|common|compan|compatible\-|conc|conduc|contact|control|contype|conv|cool|copi|copy|coral|corn|cosmos|costa|cowbot|cr4nk|craft|cralwer|crank|crap|crawler0|crazy|cres|cs\-cz|cshttp|cuill|CURI|curl|curry|custo|cute|cyber|cz3|czx|daily|dalvik|daobot|dark|darwin|data|daten|dcbot|dcs|dds\ explorer|deep|deps|detect|dex|diam|diibot|dillo|ding|disc|disp|ditto|dlc|doco|dotbot|drag|drec|dsdl|dsok|dts|duck|dumb|eag|earn|earthcom|easydl|ebin|echo|edco|egoto|elnsb5|email|emer|empas|encyclo|enfi|enhan|enterprise\_search|envolk|erck|erocr|eventax|evere|evil|ewh|exploit|expre|extra|eyen|fang|fast|fastbug|faxo|fdse|feed24|feeddisc|feedhub|fetch|filan|fileboo|fimap|find|firebat|firedownload\/1\.2pre\ firefox\/3\.6|firefox\/0|firefox\/2|firs|flam|flash|flexum|flip|fly|focus|fooky|forum|forv|fost|foto|foun|fount|foxy\/1\;|free|friend|frontpage|fuck|fuer|futile|fyber|gais|galbot|gbpl|gecko\/2001|gecko\/2002|gecko\/2006|gecko\/2009042316|gener|geni|geo|geona|geth|getr|getw|ggl|gira|gluc|gnome|go\!zilla|goforit|goldfire|gonzo|google\ wireless|googlebot\-image|gosearch|got\-it|gozilla|grab|graf|greg|grub|grup|gsa\-cra|gsearch|gt\:\:www|guidebot|guruji|gyps|haha|hailo|harv|hash|hatena|hax|head|helm|herit|heritrix|hgre|hippo|hloader|hmse|hmview|holm|holy|hotbar\ 4\.4\.5\.0|hpprint|httpclient|httpconnect|httplib|human|huron|hverify|hybrid|hyper|iaskspi|ibm\ evv|iccra|ichiro|icopy|ida|ie\/5\.0|ieauto|iempt|iexplore\.exe|ilium|ilse|iltrov|indexer|indy|ineturl|infonav|innerpr|inspect|insuran|intellig|interget|internet\_explorer|internet\x|intraf|ip2|ipsel|irlbot|isc\_sys|isilo|isrccrawler|isspi|jady|jaka|jam|jenn|jet|jiro|jobo|joc|jupit|just|jyx|jyxo|kash|kazo|kbee|kenjin|kernel|keywo|kfsw|kkma|kmc|know|kosmix|krae|krug|ksibot|ktxn|kum|labs|lanshan|lapo|larbin|leech|lets|lexi|lexxe|libby|libcrawl|libcurl|libfetch|libweb|libwww|light|linc|lingue|linkcheck|linklint|linkman|lint|list|litefeeds|livedoor|livejournal|liveup|lmq|locu|london|lone|loop|lork|lth\_|lwp|mac\_f|magi|magp|mail\.ru|main|majest|mam|mama|mana|marketwire|masc|mass|mata|mvi|mcbot|mecha|mechanize|mediapartners|metadata|metalogger|metaspin|metauri|mete|mib\/2\.2|microsoft\.url|microsoft\_internet\_explorer|mido|miggi|miix|mindjet|mindman|mips|mira|mire|miss|mist|mizz|mj12|mlbot|mlm|mnog|moge|moje|mooz|more|mouse|mozdex) [NC]
RewriteRule ^.*$ - [G]

RewriteCond %{HTTP_HOST} !^(127\.0\.0\.0|localhost) [NC]
RewriteCond %{HTTP_USER_AGENT} .*(Windows\ NT\ 6\.1\;\ tr\;\ rv\:1\.9\.2\.6\)|mozilla\/0|mozilla\/1|mozilla\/2|mozilla\/3|mozilla\/4\.61\ \[en\]|mozilla\/firefox|mpf|msie\ 1|msie\ 2|msie\ 3|msie\ 4|msie\ 5|msie\ 6\.0\-|msie\ 6\.0b|msie\ 7\.0a1\;|msie\ 7\.0b\;|msie6xpv1|msiecrawler|msnbot\-media|msnbot\-products|msnptc|msproxy|msrbot|musc|mvac|mwm|my\_age|myapp|mydog|myeng|myie2|mysearch|myurl|nag|name|naver|navr|near|netants|netcach|netcrawl|netfront|netinfo|netmech|netsp|netx|netz|neural|neut|newsbreak|newsgatorinbox|newsrob|newt|next|ng\-s|ng\/2|nice|nikto|nimb|ninja|ninte|nog|noko|nomad|norb|note|npbot|nuse|nutch|nutex|nwsp|obje|ocel|octo|odi3|oegp|offby|offline|omea|omg|omhttp|onfo|onyx|openf|openssl|openu|opera\ 2|opera\ 3|opera\ 4|opera\ 5|opera\ 6|opera\ 7|orac|orbit|oreg|osis|our|outf|owl|p3p\_|page2rss|pagefet|pansci|parser|patw|pavu|pb2pb|pcbrow|pear|peer|pepe|perfect|perl|petit|phoenix\/0\.|php|phras|picalo|piff|pig|pingd|pipe|pirs|plag|planet|plant|platform|playstation|plesk|pluck|plukkie|poe\-com|poirot|pomp|post|postrank|powerset|preload|press|privoxy|probe|program\_shareware|protect|protocol|prowl|proxie|proxy|psbot|pubsub|puf|pulse|punit|purebot|purity|pyq|pyth|query|quest|qweer|radian|rambler|ramp|rapid|rawdog|rawgrunt|reap|reeder|refresh|reget|relevare|repo|requ|request|rese|retrieve|rip|rix|rma|roboz|rocket|rogue|rpt\-http|rsscache|ruby|ruff|rufus|rv\:0\.9\.7\)|salt|sample|sauger|savvy|sbcyds|sbider|sblog|sbp|scagent|scanner|scej\_|sched|schizo|schlong|schmo|scorp|scott|scout|scrawl|screen|screenshot|script|seamonkey\/1\.5a|search17|searchbot|searchme|sega|semto|sensis|seop|seopro|sept|sezn|seznam|share|sharp|shaz|shell|shelo|sherl|shim|shopwiki|silurian|simple|simplepie|siph|sitekiosk|sitescan|sitevigil|sitex|skam|skimp|sledink|sleip|slide|sly|smag|smurf|snag|snapbot|snapshot|snif|snip|snoop|sock|socsci|sogou|sohu|solr|some|soso|spad|span|spbot|speed|sphere|spin|sproose|spurl|sputnik|spyder|squi|sqwid|sqworm|ssm\_ag|stack|stamp|statbot|state|steel|stilo|strateg|stress|strip|style|subot|such|suck|sume|sunos\ 5\.7|sunrise|superbot|superbro|supervi|surf4me|surfbot|survey|susi|suza|suzu|sweep|sygol|synapse|sync2it|systems|szukacz|tagger|tagoo|tagyu|take|talkro|tamu|tandem|tarantula|tbot|tcf|tcs\/1|teamsoft|tecomi|teesoft|teleport|telesoft|tencent|terrawiz|test|texnut|thomas|tiehttp|timebot|timely|tipp|tiscali|titan|tmcrawler|tmhtload|tocrawl|todobr|tongco|toolbar\;\ \(r1|topic|topyx|torrent|track|translate|traveler|treeview|tricus|trivia|trivial|true|tunnel|turing|turnitin|tutorgig|twat|tweak|twice|tygo|ubee|ultraseek|unavail|unf|universal|unknown|upg1|uptime|urlbase|urllib|urly|user\-agent\:|useragent|usyd|vagabo|valet|vamp|vci|veri\~li|verif|versus|via|virtual|visual|void|voyager|vsyn|w0000t|w3search|walhello|walker|wand|waol|watch|wavefire|wbdbot|weather|web\.ima|web2mal|webarchive|webbot|webcat|webcor|webcorp|webcrawl|webdat|webdup|webgo|webind|webis|webitpr|weblea|webmin|webmoney|webp|webql|webrobot|webster|websurf|webtre|webvac|webzip|wells|wep\_s|wget|whiz|widow|win67|windows\-rss|windows\ 2000|windows\ 3|windows\ 95|windows\ 98|windows\ ce|windows\ me|winht|winodws|wish|wizz|wordp|worio|works|world|worth|wwwc|wwwo|wwwster|xaldon|xbot|xenu|xirq|y\!tunnel|yacy|yahoo\-mmaudvid|yahooseeker|yahooysmcm|yamm|yand|yandex|yang|yoono|yori|yotta|yplus\ |ytunnel|zade|zagre|zeal|zebot|zerx|zeus|zhuaxia|zipcode|zixy|zmao) [NC]
RewriteRule ^.*$ - [G]

View text format

To implement the UA Blacklist, simply paste into your site’s root .htaccess file (or even better, the Apache configuration file). Upload, test, and stay current with updates and news.

Important Note

The UA Blacklist uses hundreds of regular expressions to block bad bots based on their user-agent. Each of these regular expressions can match many different user-agents. Care has been taken to ensure that only bad bots are blocked, but false positives are inevitable. If you know of a user-agent that should be removed from the list, please let me know. I will do my best to update things asap.

Bottom line: Only use this code if you know what you are doing. It’s not a “fix-it-and-forget” situation, especially for production sites. It’s more like a “fix-it-and-keep-an-eye-on-it” kind of thing, meant for those who understand how it works. As mentioned in the comments, the 2010 User-Agent Blacklist is a work in progress. Please use the UA Blacklist with caution and at your own risk.

So much more..

For those new to Perishable Press, please check out some of my other security resources:

Security is an important part of what I do around here, so please chime in with any suggestions, ideas, and comments. Thank you for visiting Perishable Press.

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105 responses to “2010 User-Agent Blacklist”

  1. Doh, I said Steve, I meant Jeff. Ugh… it’s only noon, and it already feels like a long day.

  2. Thanks Jeff!

    The only one I think I might modify would be to add a RewriteCond that basically says:

    RewriteCond %{HTTP_HOST} !^127.0.0.0

    Between the user strings, and the actual block rule. A fair number of people will use some php, curl, wget, etc on their local machine to trigger some event on their site, and the useragent list you have blocks many of these (in my case, I use curl to dump some data into a MySQL DB every minute that’s run by cron).

    Obviously YMMV, but it wouldn’t be a bad idea. Might also need one that says:

    RewriteCond %{HTTP_HOST} !^localhost

    But I’m pretty sure you can combine those. =)

  3. Jeff,

    This may be the exact thing I just wrote about. I think wordpress’s cron script may use libcurl to trigger the publish… but I could be wrong, since I don’t think I’ve ever scheduled a post for the future. =/

  4. Actually, yeah, good point.

    Might be best to do something like:

    RewriteCond %{HTTP_HOST} !^(127.0.0.1|localhost)
    RewriteCond %{HTTP_USER_AGENT} .....your_useragent_list...
    RewriteRule ^.*$ - [G]

    That way, the easy rule (is this coming from someone other than localhost) is done first, then the hard rule is done second.

    I don’t think an [OR] is needed. This would be an “AND”… so, NOT localhost, AND one of these useragents. If we use an [OR], it would still trigger if the localhost was connecting with curl.

    Or am I thinking about this wrong? Again, this day has been really long already.

  5. Sounds like a job for Splunk! =)

  6. Steve, people are copying your current list, and might not update it.

    And people will not necessarily contact the administratior of a site. They might just give up. Or write a post in their blog that Google Reader is working with some feed but buggy Liferea isn’t. Or complain to us Liferea developers about some non-working Feed. And then I might be the one spending time on debugging why the feed works with Google Reader (not blocked) but not with Liferea (blocked).

    When doing blacklisting each false positive is one too many. And there are *many* in your list.

    Firefox 3.0 still has a market share around 2%, so your blacklisting blacklisting blocks 2% of all site visitors/customers.

    On the other hand, e.g. w3m is a fine albeit exotic browser with a userbase so small that I really wonder how it made it into your blacklist – and an administrator might not get user reports for that false positive for months.

  7. Doh, I had the same Jeff/Steve mixup. Sorry!

  8. Update: The following items have been removed from the UA Blacklist:

    • w3c
    • w3m
    • lifearea
    • firefox/3.0
    • firefox/3.0.10

    Here are the remaining Firefox-related user-agent strings that appear in the list (with escape characters removed):

    • firefox/0
    • firefox/1
    • firefox/2
    • mozilla/firefox
    • pt-BR; rv:1.9.0.3) Firefox/3.0
    • pt-BR; rv:1.9.0.18) Firefox/3.0
    • firedownload/1.2pre firefox/3.6

    The last four of these aren’t legit, and the first three block very old versions, which according to my stats is a very small percentage of visitors. We’re blocking many more bad bots with these than actual browsers.

    Some notes:

    • @Eric Curtis: The removal of the “w3c” should resolve any W3C Validator issues.
    • The Windows-related user-agents remain in the list until I can find an authoritative user-agent reference for Windows stuff.

    That’s it for now.. keep any suggestions coming, and I’ll do my best to keep things current. Thanks :)

  9. @Louis: Hey just saw your comment – somehow missed it initially.

    I’m not sure why a user-agent blacklist would stop WordPress from executing PHP on the server. If there is some sort of WP UA string involved in the process, we could remove the regex match from the list.

    I’ll keep my eyes on it. Thanks for the feedback.

  10. @RS: Great timing – adding that condition is a great idea, and may indeed fix the issue with WordPress scheduling mentioned in previous comment. If so, sweet. :)

    I’ll be updating the list again as soon as I can think thru using an [OR] flag for the first condition in either list.

  11. RS, I’d say the way the list gets constructed is wrong. I would say you cannot create a blacklist this way in an automated way and then try to find all false positives.

    Jeff still claims the list was “carefully constructed based on rigorous server-log analyses” although the list is in reality full of false positives – I better don’t tell publically what I think about that.

    Another interesting question is whether people using “evil bots” really use identifyable user agent strings as the blog claims. If I’d write an evil bot I’d use the user agent string of the latest Firefox and all this user agent blocking wouldn’t affect my evil bot. If Jeff has data how many percent of *all* accesses this blacklist actually blocks that would be interesting information.

  12. Jeff Starr 2010/08/11 1:00 pm

    Yes, definitely no [OR] flags! – otherwise the list would block everything that isn’t localhost. In any case, the list has been updated with these helpful conditions. Thanks to RS for the suggestion! :)

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