Malicious PDF — malware analysis report

Static analysis result for SHA-256 43ed7532a4636630…

MALICIOUS

PDF

73.0 KB Created: 2021-06-13 01:55:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 89023c67f4537a53ec4035a5350e5d53 SHA-1: 3a516bc0b7a60a5cb6c4ea9c10dea3db793e32c9 SHA-256: 43ed7532a4636630976f1a34b410abec90f222b6f9d16e7b6fc23b7655d9a524
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous external URIs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and 'Qt', indicating it was likely generated by a tool rather than being a legitimate document. The presence of multiple PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics strongly indicates a phishing or malware distribution attempt.

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=aristocats+marie+coloring+pages PDF link annotation
    • https://audit-advisers.com/userfiles/file/6926977289.pdfIn PDF document text
    • http://drthchowdary.net/userfiles/file/79378987975.pdfIn PDF document text
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/e9de52141c747d6b4a2c83bf69334077/6508052460.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fc18e9d2a4---gitiraxerulewapakof.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/d59693f983bf944cad5641b1bf78a24b/mupalenekapudezuwa.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083c3d825163---solekajixojanuma.pdfIn PDF document text
    • http://princeworldwide.com/multimedia/userfiles/file/bolijiwurubegifibalezozi.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/87651642871.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b19f420a30b---kivimikuwoduxoguzu.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086a4eed974c---15882945042.pdfIn PDF document text
    • https://mariellatriolo.it/public/file/32761175316.pdfIn PDF document text
    • http://rufullthrottle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e4f39c4ca1---73660679258.pdfIn PDF document text
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/afc4c3b93cc13d7aaaa1362c744851a4/tutatow.pdfIn PDF document text
    • http://www.anjhimayath.com/upload/file/40732182530.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_off0000dfb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFB4 5244 bytes
SHA-256: 24d2240e12a3c1f1e49ce0b061115c5d6f33fe6fd62559379ce7886d61de20e9
font_01_sfnt_off0000f176.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF176 10544 bytes
SHA-256: f4b5d7713a53ad2250c7fa60b4909f9817d70b0dc746c3d6f7c40ea4276f22da