Malicious PDF — malware analysis report

Static analysis result for SHA-256 728b8f03b4575332…

MALICIOUS

PDF

114.3 KB Created: 2021-09-08 19:06:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 22f3c6bc982aa16c84fd42bb4ff5ba65 SHA-1: a1df19cfa4db98f16ef64b52eb3b3d7c8f0a299b SHA-256: 728b8f03b45753327c6a5e0bf0471bfc4ef9c999168e08b8da94406b1ac5ed59
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF contains numerous embedded URLs, many pointing to disposable domains, characteristic of a link farm designed to obscure the final destination. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic confirms this pattern, suggesting the PDF's primary purpose is to redirect users through a chain of links, likely leading to phishing content or malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://lecourbe.dk/userfiles/file/dolajaseni.pdf In PDF document text
    • http://supermarketdv.ru/files/file/xubaza.pdfIn PDF document text
    • http://mcutech.net/files/vozof.pdfIn PDF document text
    • http://budohurtsa.pl/userfiles/file/55616598747.pdfIn PDF document text
    • http://sunnysolutions.it/uploads/assets/file/sokaziger.pdfIn PDF document text
    • http://tumakuruvoice.com/tumkurvoice/ckeditor/ckfinder/userfiles/files/gifelilobovubuf.pdfIn PDF document text
    • http://sutinlawkrabi.com/ckfinder/userfiles/files/nixewo.pdfIn PDF document text
    • http://baove247.org/upload/files/9439466238.pdfIn PDF document text
    • http://dalboncostruzioni.it/userfiles/files/salataximofafitud.pdfIn PDF document text
    • https://pasarangroup1.com/contents/files/27533920999.pdfIn PDF document text
    • http://www.espace-hotelier.com/ckfinder/userfiles/files/jikamekutodofakolubane.pdfIn PDF document text
    • http://noxsun.com/jingkelun/userfiles/files/20210904130355.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/161332f2948816---62108207235.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/28747218332.pdfIn PDF document text
    • https://sistemagestiondpr.com/userfiles/file/32369187011.pdfIn PDF document text
    • http://conniecorsentino.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jetupesepixidekerujitif.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137d07ba5af8---17852840491.pdfIn PDF document text
    • https://tyeetomsfishing.com/userfiles/file/sajifozada.pdfIn PDF document text
    • https://songod.vn/uploads/image/files/mowinirobepumaf.pdfIn PDF document text
    • https://livre-d-art.com/ckfinder/userfiles/files/78908751450.pdfIn PDF document text
    • https://hirurgija.me/files/jofozogemoroxagas.pdfIn PDF document text
    • https://santehsevast.ru/userfiles/files/13375176355.pdfIn PDF document text
    • http://moristas.com/userfiles/files/xeteronamuxebaletoliw.pdfIn PDF document text
    • http://instant-image.net/UserFiles/Site/File/80085078628.pdfIn PDF document text
    • https://suativisamsungtaihanoi.net/upload/files/70897440322.pdfIn PDF document text
    • http://vino-charlie.cz/userfiles/file/vapemekusefowuvufol.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=building+economics+theory+and+practice+pdfPDF 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_off000159fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x159FE 11332 bytes
SHA-256: 3ea17a862fdab859d09262ee67278c3215dff9e96fa1dcc3b2f04c86d03f9a8d
font_01_sfnt_off00017448.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17448 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00018c5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18C5A 17788 bytes
SHA-256: 93cc51bcd278c75f4ac40c2dd92ee7fbd081116913d32b7b97848a36bd8462ed