Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b810d46af7f2a74…

MALICIOUS

PDF

74.6 KB Created: 2021-09-15 17:03:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: a0d8414a2714a704ae657c4ee0123bab SHA-1: 670677079e6028ab232b0bcd7ff4c77eefccc5e5 SHA-256: 1b810d46af7f2a7471ff865463b3751ed346ef82b0dfb7cb274a4a2fe41b0809
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with several URLs pointing to compromised WordPress upload directories. The document body is heavily obfuscated and unreadable, suggesting it's designed to evade analysis rather than convey information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140049421839---zonoralor.pdf In PDF document text
    • http://ilkconstruction.com/Images/Media/files/zazeketebokexolikuremeri.pdfIn PDF document text
    • http://kastely-vacduka.hu/fileok/file/pakuwesumuxeb.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f93b8dfe16---45030515562.pdfIn PDF document text
    • https://doktor-ara.com/userfiles/files/12263892482.pdfIn PDF document text
    • https://drivetripper.com/userfiles2020/files/49321730137.pdfIn PDF document text
    • https://tasteadmin.com/ckfinder/core/connector/php/custom/wysi_uploads/files/87665417350.pdfIn PDF document text
    • http://thaymanhinhlaptop.com/userfiles/file/kaxalesakubi.pdfIn PDF document text
    • http://wiskind.com/filespath/files/20210903150901.pdfIn PDF document text
    • http://medicamarsala.it/userfiles/files/kevebuka.pdfIn PDF document text
    • https://lose-weight.tw/upload/files/9304274900.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/825e30123cf61ff00485f896836c40a2/bepemegiluwokelejafej.pdfIn PDF document text
    • http://www.sindafaz.com.br/admin/editor/ckfinder/userfiles/files/bezupokeraxew.pdfIn PDF document text
    • http://duhochoangthanh.com/upload/files/22212610198.pdfIn PDF document text
    • https://pet-fashion.ro/mm/file/80973078805.pdfIn PDF document text
    • http://vervesimuhub.com/userfiles/file/58349247841.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161333d3da6c9e---guzadobunukinuvosoxovejud.pdfIn PDF document text
    • https://www.stnedu.com/ckfinder/upload/files/98165420992.pdfIn PDF document text
    • https://radiosmile.hu/upload/file/25686430899.pdfIn PDF document text
    • https://wrd13.com/force/file/gavinovitebixego.pdfIn PDF document text
    • http://tecs4.com/intranet/ckfinder/userfiles/files/66906757252.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136fe4f7f4d5---gajiri.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=max+kellerman+erin+manningPDF link annotation
    • 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_off0000bfff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFFF 10252 bytes
SHA-256: 58e52e9aff6e0c29e74c0dccb00690c2b5ba66f0b1737b81dcd0c7959ce12c55
font_01_sfnt_off0000d6ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6EE 17660 bytes
SHA-256: 2cc919211c259a54d93a4772a42ffe5e06230a0ea7d406b4c7682101663dcddd
font_02_sfnt_off00010485.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10485 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1