I place this inside /etc/nginx/conf.d

agentblock.conf

map $http_user_agent $bad_agent {
        default 0;
        "~*^[Ww]eb[Bb]andit" 1;
        "~*^Acunetix" 1;
        "~*^binlar" 1;
        "~*^BlackWidow" 1;
        "~^Bolt" 1;
        "~*^casper" 1;
        "~*^checkprivacy" 1;
        "~*^ChinaClaw" 1;
        "~*^clshttp" 1;
        "~*^cmsworldmap" 1;
        "~*^comodo" 1;
        "~*^Custo" 1;
        "~^Default" 1;
        "~*^diavol" 1;
        "~*^DIIbot" 1;
        "~*^DISCo" 1;
        "~*^dotbot" 1;
        "~*^eCatch" 1;
        "~*^EirGrabber" 1;
        "~*^EmailCollector" 1;
        "~*^EmailSiphon" 1;
        "~*^EmailWolf" 1;
        "~*^extract" 1;
        "~*^ExtractorPro" 1;
        "~*^EyeNetIE" 1;
        "~*^feedfinder" 1;
        "~*^FHscan" 1;
        "~*^FlashGet" 1;
        "~*^flicky" 1;
        "~*^GetRight" 1;
        "~*^GetWeb!" 1;
        "~*^Go-Ahead-Got-It" 1;
        "~*^g00g1e" 1;
        "~*^Go!Zilla" 1;
        "~*^grab" 1;
        "~*^GrabNet" 1;
        "~*^Grafula" 1;
        "~*^harvest" 1;
        "~*^HMView" 1;
        "~*^ia_archiver" 1;
        "~*^InterGET" 1;
        "~*^InternetSeer.com" 1;
        "~*^jakarta" 1;
        "~*^Java" 1;
        "~*^JetCar" 1;
        "~*^kanagawa" 1;
        "~*^kmccrew" 1;
        "~*^larbin" 1;
        "~*^LeechFTP" 1;
        "~*^libwww" 1;
        "~*^Maxthon$" 1;
        "~*^microsoft.url" 1;
        "~*^miner" 1;
        "~*^Mozilla.*Indy" 1;
        "~*^Mozilla.*NEWT" 1;
        "~*^MSFrontPage" 1;
        "~*^Navroad" 1;
        "~*^NearSite" 1;
        "~*^NetAnts" 1;
        "~*^NetSpider" 1;
        "~*^NetZIP" 1;
        "~*^nutch" 1;
        "~*^Octopus" 1;
        "~*^PageGrabber" 1;
        "~*^pavuk" 1;
        "~*^pcBrowser" 1;
        "~*^PeoplePal" 1;
        "~*^planetwork" 1;
        "~*^psbot" 1;
        "~*^purebot" 1;
        "~*^pycurl" 1;
        "~*^RealDownload" 1;
        "~*^ReGet" 1;
        "~^Rippers" 1;
        "~*^SeaMonkey$" 1;
        "~*^sitecheck.internetseer.com" 1;
        "~*^SiteSnagger" 1;
        "~*^skygrid" 1;
        "~*^SmartDownload" 1;
        "~*^sucker" 1;
        "~*^SuperBot" 1;
        "~*^SuperHTTP" 1;
        "~*^Surfbot" 1;
        "~*^tAkeOut" 1;
        "~^Teleport" 1;
        "~^Toata" 1;
        "~*^turnit" 1;
        "~*^vikspider" 1;
        "~*^VoidEYE" 1;
        "~*^WebAuto" 1;
        "~*^WebCopier" 1;
        "~*^WebFetch" 1;
        "~*^WebLeacher" 1;
        "~*^WebReaper" 1;
        "~*^WebSauger" 1;
        "~*^WPScan" 1;
        "~*^WebStripper" 1;
        "~*^WebWhacker" 1;
        "~*^WebZIP" 1;
        "~*^Wget" 1;
        "~*^Widow" 1;
        "~*^WWW-Mechanize" 1;
        "~*^WWWOFFLE" 1;
        "~*^Yandex" 1;
        "~*^Zeus" 1;
        "~*^zmeu" 1;
        "~*AhrefsBot" 1;
        "~*CazoodleBot" 1;
        "~*discobot" 1;
        "~*ecxi" 1;
        "~*GT::WWW" 1;
        "~*heritrix" 1;
        "~*HTTP::Lite" 1;
        "~*HTTrack" 1;
        "~*ia_archiver" 1;
        "~*id-search" 1;
        "~*id-search.org" 1;
        "~*IDBot" 1;
        "~*IRLbot" 1;
        "~*LinksManager.com_bot" 1;
        "~*linkwalker" 1;
        "~*lwp-trivial" 1;
        "~*MFC_Tear_Sample" 1;
        "~Microsoft" 1;
        "~*MJ12bot" 1;
        "~*panscient.com" 1;
        "~*PECL::HTTP" 1;
        "~*PHPCrawl" 1;
        "~*PleaseCrawl" 1;
        "~*SBIder" 1;
        "~*Snoopy" 1;
        "~*Steeler" 1;
        "~*URI::Fetch" 1;
        "~*urllib" 1;
        "~*webalta" 1;
        "~*WebCollage" 1;
        "~*zermelo" 1;
        "~*ZyBorg" 1;
}