Malicious PDF — malware analysis report

Static analysis result for SHA-256 1900ccebbba035e9…

MALICIOUS

PDF

81.6 KB Created: 2021-09-02 14:52:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 6e729e3038a7f8fb3da5661f2045c74d SHA-1: 8e71436e6a8831fb8e1ba638060b8e030119be10 SHA-256: 1900ccebbba035e9ea4fbcfb6e6f35ba9675ee1047e473b62815ebb64c917410
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs point to compromised CMS uploads and disposable hosting, indicating a link farm designed to redirect users. The primary attack pattern involves using the document as a lure, likely via spearphishing, to direct users to malicious or SEO-abused websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nomylo.ru/uplcv?utm_term=reddy+forensic+medicine+pdf+free+download PDF link annotation
    • http://servmed.net/userfiles/file/wenatukexedejimagijex.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/a8ff5afc296cd471e756b2e675f34497/tabapoxotezera.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/160bce6f09324d---jojirujigejafe.pdfIn PDF document text
    • http://buyyoutubelikes.com/ci/userfiles/files/nokifetavulimirigusixizis.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/e901e459cb49a81dfb5ba96fc4d952cb/78272169859.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160945bafa79a3---rifukidanidibulagiwuw.pdfIn PDF document text
    • http://humanitool.ru/userfiles/file/rozonebolumesimunipoxigak.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160d95c4577e55---22626785655.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609434782cca2---gikiritigotawu.pdfIn PDF document text
    • http://quick-thailand.com/images/uploads/file/samaxebuxirujukulano.pdfIn PDF document text
    • http://gancza.pl/userfiles/file/rajixofirowaraxipirepu.pdfIn PDF document text
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d399923ac7---jaganuzubup.pdfIn PDF document text
    • https://adverto.ee/userfiles/file/99593401088.pdfIn PDF document text
    • http://skyline1968.com/clients/74864/File/6897688479.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/f707ac8a836a16f2e2fd57b2e623db11/32766824734.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/160fc9884b81aa---18889629951.pdfIn PDF document text
    • https://nguyenthelong.net/userfiles/files/94598414526.pdfIn PDF document text
    • https://attackworkoutprogram.com/app/webroot/files/ckfinder/userfiles/files/1917487409.pdfIn PDF document text
    • http://tfh-filter.hu/_user/file/koxekemuvusadamuvepe.pdfIn PDF document text
    • http://happyland-nsk.net/ckfinder/userfiles/files/sebukoboxaletasufifurofi.pdfIn PDF document text
    • http://n2nlah.org/UserFiles/file/77155595937.pdfIn PDF document text
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9c176f60c---saxupinosupitidunojekode.pdfIn PDF document text
    • http://animationcoach.com/userfiles/file/dekilawigeripizom.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/21130116956.pdfIn PDF document text
    • https://dongcohonda.com/userfiles/file/3084429714.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_off0000d8d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8D4 17860 bytes
SHA-256: 7509b7bec7eb67526db9e9a543b1fe79c8f46865bd3c9f8b4845c9fd16f7b4af
font_01_sfnt_off00010763.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10763 10928 bytes
SHA-256: d1c449c5179c43960b452bea2462e81efe8d507be72daf453511a5f718e99371
font_02_sfnt_off000120c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1