Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4d4663bcfc0f186…

MALICIOUS

PDF

78.1 KB Created: 2021-10-13 22:51:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 651248078938554a63855400a6ce5365 SHA-1: e04a376db594afa2ca52da285f70a3701b341cfb SHA-256: c4d4663bcfc0f1863f4df51b4e48ee046ba5722d3c0f0ec6d63222e6668d440a
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS uploads, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and numerous external links are indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://chcial.ru/uplcv?utm_term=ductal+hyperplasia+without+atypia PDF link annotation
    • http://struttur-arch.it/userfiles/files/pabepitemesedilaz.pdfIn PDF document text
    • http://pileshoppen.dk/userfiles/file/paxulozavigates.pdfIn PDF document text
    • http://kingtonkatsu.com/uploads/files/xifomupinitede.pdfIn PDF document text
    • http://posekatzahradu.cz/files/file/lanivujixisapomowunel.pdfIn PDF document text
    • https://jlgardner.org/home/jlg/public_html/ckfinder/userfiles/files/xovonufafizusanewatilaboz.pdfIn PDF document text
    • https://tomclarkvoiceovers.com/userfiles/files/44500759422.pdfIn PDF document text
    • http://chipublichouse.com/ckfinder/userfiles/files/rebidemeviza.pdfIn PDF document text
    • http://mothertheresapublicschool.com/userfiles/file/4595500642.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/e858a2b9db7bd0fd88e0b4765fb1c88d/mebigitalivitesevepigeg.pdfIn PDF document text
    • https://shriramsteels.in/public/ckfinder/userfiles/files/29247286562.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613246a0a57cc---77744749304.pdfIn PDF document text
    • http://tuttotop.com/userfiles/files/dafupeza.pdfIn PDF document text
    • https://asthasupermarket.com/userfiles/file/93960978338.pdfIn PDF document text
    • http://cortocircuito.trialpanel.com/images/Upload/files/megexolutamoruduli.pdfIn PDF document text
    • https://xn--p3t29jo1ed4o4xw.tw/upload/files/jabosuwogi.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/161359293aeb29---vabesenifova.pdfIn PDF document text
    • http://meubelenindex.nl/images/uploads/libamewinebaf.pdfIn PDF document text
    • http://kolaykanal.com/userfiles/files/desuzitufekubosufados.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/41513541667.pdfIn PDF document text
    • http://ritadas.in/userfiles/file/zopeniritomadibu.pdfIn PDF document text
    • https://easyown.ddproperty.com/datas/files/13954904310.pdfIn 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://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_off0000c5b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ddca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDCA 20232 bytes
SHA-256: 2333c84d12f98e758284822338458abcfcd372b0191a03b170f48cb5e06de5ab
font_02_sfnt_off000112a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112A3 10668 bytes
SHA-256: 5e58954aaeae49a51764a514f8253fedaa13d3d253b4624ae6ab3480ea8427d3