Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d6f9c485f77a615…

MALICIOUS

PDF

89.0 KB Created: 2021-09-05 07:17:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 81b37efc4e776943a2d231168e07de61 SHA-1: 0c8a64180452adb2d27143986bfa1138024da953 SHA-256: 4d6f9c485f77a6157e0feb4165d6da8b5f5881f6ac6025f1033e53d27590be07
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm or phishing campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool rather than user-readable content, reinforcing the non-legitimate nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ddfd4dacd4---84432825550.pdf In PDF document text
    • http://dennehylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/64973285001.pdfIn PDF document text
    • http://rogalafamilyreunion.org/clients/0/0d/0db8e8e54aa701f14f52e26b989c21c2/File/xeselatebasegabegiwutubuv.pdfIn PDF document text
    • http://ibb-online.ru/f/file/milalixapekirifabawe.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/wolatapinafuv.pdfIn PDF document text
    • http://clubesquilacoma.com/uploads/files/galop.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609932638f4ab---80375069132.pdfIn PDF document text
    • https://syntellect.ru/Repository/file/pafiwunodumobulefaworome.pdfIn PDF document text
    • https://etest.vn/app/webroot/uploads/files/67320176947.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/75179654495.pdfIn PDF document text
    • http://levakov132.ru/userfiles/file/dolunalugi.pdfIn PDF document text
    • http://petra-dario.info/upload/datoteke/guvovivonafebemomeduw.pdfIn PDF document text
    • https://viveironativodevicosa.com.br/ckfinder/userfiles/files/sobufomogazowugesafu.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/f99d9d432f40806a8c3581ec91ad644b/97950049967.pdfIn PDF document text
    • http://kythuatviet.vn/uploads/userfiles/file/nobeguxirifuj.pdfIn PDF document text
    • http://fresh-j.info/images/uploadedimages/file/fusaro.pdfIn PDF document text
    • https://bibliotheque-des-arts.com/ckfinder/userfiles/files/89066580681.pdfIn PDF document text
    • https://cowichanseniors.ca/userfiles/file/lekuraxubamisefurin.pdfIn PDF document text
    • http://tasarimak.net/ckfinder/userfiles/files/benolovunaguwodevukuta.pdfIn PDF document text
    • http://wahluenfty.com/userfiles/mujoripuwe.pdfIn PDF document text
    • https://yourlightingbrand.com/wp-content/plugins/super-forms/uploads/php/files/4aae33a0d6f39bf43a72c21e786cc712/32265012537.pdfIn PDF document text
    • http://kondicionery-dolgoprudny.ru/upload_picture/file/sawuresirazezuvuvevixe.pdfIn PDF document text
    • https://amatnieks.com/pictures/image/13477171799.pdfIn PDF document text
    • http://rufullthrottle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce1fce0ed2---95456302803.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=rounding+whole+numbers+ks2+worksheetPDF 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_off0000f285.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF285 11116 bytes
SHA-256: 193fae35d8b19f060ccf8e5d82857d50d79852cee5223a31bb89ea2d2d7147df
font_01_sfnt_off00010c21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C21 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012433.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12433 19076 bytes
SHA-256: 7e02e73e435b4fe2e3f5b373a9e4735e078002aa3c19ba8e55b027c77b3e9433