Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a0f4b5e09070d77…

MALICIOUS

PDF

66.4 KB Created: 2021-06-06 18:02:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 70a22993b68ac094383e0237629fe96e SHA-1: 8e369dd854a21f1f988389bac531b7f1e4c987e0 SHA-256: 5a0f4b5e09070d77d145bd45d231c7041814fe93b0a7a624e796aac0060c0e34
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a phishing or malware distribution campaign. The document body, though heavily obfuscated, appears to be a lure related to an 'answer key', likely intended to trick users into clicking the malicious links.

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://irlanc.ru/uplcv?utm_term=integrated+chinese+workbook+answer+key PDF link annotation
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa34de7635f---69628134343.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/16078db0cbbf06---44640657771.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/d07d7cf0758e3a1c5628325254b480d2/64976497792.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/c48dc59a879e29822075c21f1a2d9cb7/nufuditi.pdfIn PDF document text
    • https://e-lightingcontrols.com/wp-content/plugins/super-forms/uploads/php/files/7b22b1103143bcfd194f593e83103408/jinujisumukatake.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/30919438b4efdef2984ff1532ef57f41/1611531664.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1609db14166807---16628041239.pdfIn PDF document text
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/f51862a7fad8182d042a3819aabe5756/juvabosuxoba.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b2dae09d0f5---wefusudafakazo.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/f6fb7cc1bb69637ced1fb6e40a4f21b4/53704431266.pdfIn PDF document text
    • https://globalclassic.org/wp-content/plugins/super-forms/uploads/php/files/06rkfcb0bf8cd6qe919td9o7as/rotumuxolewokekukawiju.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16077ea0eadf65---vulojodazojuvukexa.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/d9480d2bb56823f09b4e81df45d7c58d/37163869624.pdfIn PDF document text
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/00064682d5871886aee25b4315c93a8f/20718070347.pdfIn PDF document text
    • https://lemanssrl.it/file/marasuvixarujusaseba.pdfIn PDF document text
    • http://businessdevelopmentcenter.pl/uploads/userfiles/files/mirir.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_off0000c6a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6A7 5504 bytes
SHA-256: 4ebde81bd618179dd44d8ad9a0851c8e0d8228c2059885cdaf35c6e57b4e50fc
font_01_sfnt_off0000d972.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD972 9668 bytes
SHA-256: f7305969874f847d056faebf77a7bf28df437146caafdc97d14beca7eccd7042