Malicious PDF — malware analysis report

Static analysis result for SHA-256 a50681d6ff1d4cf1…

MALICIOUS

PDF

76.5 KB Created: 2021-09-07 01:46:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 2c79f2e086b9d740880bca2eeb40f315 SHA-1: cff72a1f837be69faae529bc818c5b73cdd1cb31 SHA-256: a50681d6ff1d4cf1fa2cfc813f9dd49a09aef889ba9ae98d241541c06e651b04
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file exhibits characteristics of a phishing or malware distribution lure, as indicated by multiple heuristics flagging it as a link farm pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were directly extracted, the presence of numerous external URLs suggests the document is designed to redirect the user to a malicious site, likely to download a second-stage payload or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://coretry.ru/uplcv?utm_term=singular+and+plural+words+in+english+pdf PDF link annotation
    • http://gpkoaee.ru/ckfinder/userfiles/files/85338206043.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607096c25aa65---65176773005.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1610d0e3cd5428---16451371175.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/f0h8i0te4smkcmuou0naoag5lk/55789421079.pdfIn PDF document text
    • https://rmp-familienanzeigen.de/cms/files/perefipepimi.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/fodov.pdfIn PDF document text
    • https://tcremich.lu/files/files/82543190847.pdfIn PDF document text
    • http://28777886.com/Lpf/UPFILE/userfiles/files/5567163184.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1607e23baa0114---wufidibomazil.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/35ad775d5aa52efe83e1e13a713ccdc2/buwifer.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608b80516a286---dedovefidatufufe.pdfIn PDF document text
    • https://planet-for-events.de/userfiles/file/sunaxiranexedekemukolapes.pdfIn PDF document text
    • https://mygenius.ru/admin/ckfinder/userfiles/files/tumofe.pdfIn PDF document text
    • http://uniradioweb.info/userfiles/files/wowovowefa.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/k93v92fh4hpn8nq4nuj54lqkf8/bugimetefaga.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3925fedd0a---nufepi.pdfIn PDF document text
    • http://wintec-samu.hu/uploads/files/22394259559.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/i0d40mkuitm6ekh0hnl62aa8tt/30551727450.pdfIn PDF document text
    • http://e-photo.lv/ckfinder/userfiles/files/sojawokujefegagabez.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/e197fd7a3f2a86f87e9d2f639c4c81af/dokukixi.pdfIn PDF document text
    • http://fisioterapiasuzzara.it/userfiles/files/gilasogosizixuronelafij.pdfIn PDF document text
    • http://hyunbulsa.org/~ewedd2/userfiles/file/98551485267.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/1f2ab0d7800fb1d852993ccd6cd0f191/85310593808.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/5c1dafefc68e39877065dfaee4eab7e4/nixapibaluwesidijixosene.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c0fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0FB 10940 bytes
SHA-256: a8f8cc1acf5e03050b3a2c7240e322acbb778acfed71e9bcf90154b6f395c141
font_01_sfnt_off0000da10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA10 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f222.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF222 19252 bytes
SHA-256: 2d6cb1f027a204f7c1866acc921a9cc42de3b916332530562b2cef32aeab05bb