Malicious PDF — malware analysis report

Static analysis result for SHA-256 2303d5ac7d720b11…

MALICIOUS

PDF

70.2 KB Created: 2021-06-06 14:02:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: a941623b758015e236467079d97bfd1d SHA-1: 577671b5bc29dacfb90b179f25a1cf9383873048 SHA-256: 2303d5ac7d720b113b8bcce526576557cb812d47f74ebcf7863bb7183533b3d5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains multiple links to external websites, many hosted on compromised WordPress installations, suggesting a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://medvor.ru/uplcv?utm_term=ejercicios+de+radicaci%25C3%25B3n+de+n%25C3%25BAmeros+enteros+resueltos PDF link annotation
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/369673e99052245c015d4c73e5fff1fc/zazefezamokamajokofub.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071bb4f76400---rimed.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a4f888aa3d3---fudoboniladetaditafisa.pdfIn PDF document text
    • http://bukharasuwanee.com/sites/default/files/file/fiwibezozuxafakubulezi.pdfIn PDF document text
    • https://mytopics.it/uploads/file/jorogekopiroz.pdfIn PDF document text
    • https://clubelsendero.com/img_pag/file/nagos.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/20644575337.pdfIn PDF document text
    • http://timebank.ru/sites/default/files/photos/pagefile/71328844186.pdfIn PDF document text
    • http://lycee-elm.org/userfiles/file/wezifaniserotalajiwirawix.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb10308b54---37322388877.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/7uuf3outohapir5rgravnljap3/lozovogoxudunudawapore.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/16091c5db12539---mitafirop.pdfIn PDF document text
    • http://thessalonikiflights.com/files/files/8799793305.pdfIn PDF document text
    • http://rotarylaspalmas.org/documentos/file/63543625503.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/6bff40580576aa976f616af1b49306f4/59261943043.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/8bebee2f4a9a4c80d87da8eeeb752b44/13048905427.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d088.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD088 5372 bytes
SHA-256: c513d0d6ac6366ddc2f200e9bbd3763af52b36a9871ce70dd190989f6dcda0cf
font_01_sfnt_off0000e23c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE23C 12080 bytes
SHA-256: 6d42dfd22386f71797e27343af64ac238e48598d1302022e2ea95e794e10e413