Malicious PDF — malware analysis report

Static analysis result for SHA-256 25145be298f4fd71…

MALICIOUS

PDF

86.0 KB Created: 2021-09-20 14:56:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 3f3649ba0c18660166ccf04add2de96c SHA-1: 822aa5c7620b4461b922460365727b551754239f SHA-256: 25145be298f4fd716c0eec3342a36deac81ff811266b34c6efe617724907dc2f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains numerous embedded URLs pointing to various PDF files hosted on different domains, suggesting a link farm or content distribution network. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a high number of distinct hosts, reinforcing the link farm hypothesis. While no scripts were explicitly extracted, the nature of the embedded URLs and the overall structure suggest a phishing or malicious content delivery attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://hosungtour.com/FileData/ckfinder/files/20210903_20DF35660AE2E3EC.pdf In PDF document text
    • http://www.gyndoktors.de/ckfinder/userfiles/files/92983311658.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16146441d07d71---61109437703.pdfIn PDF document text
    • http://silver.jo/ckfinder/blanc/files/fovil.pdfIn PDF document text
    • https://thietbivesinhsonhoa.com/webroot/img/files/fapezelemil.pdfIn PDF document text
    • http://sziazsauto.com/uploads/files/71158562466.pdfIn PDF document text
    • http://hkalc.com/userfiles/doxetapanajiweme.pdfIn PDF document text
    • http://feg.vn/uploads/files/sewodanesu.pdfIn PDF document text
    • http://oreade-breche.fr/userfiles/file/jujoxupunalir.pdfIn PDF document text
    • http://rioairporttransfer.com/ckfinder/userfiles/files/98019945868.pdfIn PDF document text
    • http://usairsprings.com/userfiles/file/90931743060.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/8e1a9a98e663cfb0ae627e8cfd3c52eb/situsefesabena.pdfIn PDF document text
    • http://itineraire-consulting.com/ckfinder/userfiles/files/wubabunazivasasukego.pdfIn PDF document text
    • http://systemsbiology.at/uploads/assets/file/11529847778.pdfIn PDF document text
    • http://yourbuilding.ru/userfiles/files/94030060974.pdfIn PDF document text
    • http://mvdeastudio.it/userfiles/files/nitenulam.pdfIn PDF document text
    • https://coolingrealestate.com/your-home-cleaner/FCKuploads/file/bagezisevutebaxapolax.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/74278885099.pdfIn PDF document text
    • https://hotelite.in/userfiles/file/49028560443.pdfIn PDF document text
    • http://etcpremium.com/userfiles/files/66242127253.pdfIn PDF document text
    • http://www.sport-konyv.hu/userfiles/file/24338274996.pdfIn PDF document text
    • http://kcntanduc.vn/img_duhoc/files/pabenuguzedovaruji.pdfIn PDF document text
    • https://gifarlcm.com/upfiles/editor/files/famalexipigaxo.pdfIn PDF document text
    • https://www.asoriofrio.org/ckfinder/userfiles/files/63176958037.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=how+can+i+watch+true+to+the+game+2PDF 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_off0000eba2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000103b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B4 17692 bytes
SHA-256: 92244a236fa4574021360a03ee202aeee5b127945ce9174da82e8a09cdccf4dd
font_02_sfnt_off000131e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131E0 10760 bytes
SHA-256: 990476d8a41725b8ebbf667cf12e2ad9edbe0c36c6ecd8323e3b30e84e0de098