Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb1bcbfd52a91c13…

MALICIOUS

PDF

71.8 KB Created: 2021-09-27 08:19:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 6bf18ab351878c196f3922977ba5fa80 SHA-1: 08222d6e32bef7d92228b678081f072c27fe1807 SHA-256: fb1bcbfd52a91c138e40e55dfc3879539084f5e855c1d62f9d9dd5b368286ff7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The presence of PDF-specific heuristics like PDF_SEO_DISPOSABLE_LINK_FARM further supports the conclusion that this PDF is part of a campaign to distribute malicious content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://angelojrobles.com/admin_initial_test/userfiles/file/sonuselobu.pdf In PDF document text
    • https://hanurichurch.org/ckfinder/userfiles/files/bexikejubovuwab.pdfIn PDF document text
    • http://h04ydivan.ru/userfiles/file/lufijevapezikokijumozo.pdfIn PDF document text
    • https://shinaltd.ru/images/file/10154613039.pdfIn PDF document text
    • http://kvarkeno56.ru/userfiles/file/zekifev.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/16149ecee27b78---8688079965.pdfIn PDF document text
    • http://dalnoboy.net/data/filestorage/upload/files/gavibesogunonuzemufirux.pdfIn PDF document text
    • https://healthlantern.com/ckeditor/ckfinder/userfiles/files/79759790805.pdfIn PDF document text
    • http://studiotecnicostradi.eu/userfiles/files/xenirariluvono.pdfIn PDF document text
    • https://middletonchambers.com/ckfinder/userfiles/files/desinajekoxub.pdfIn PDF document text
    • http://yasairamenbar.com/uploads/files/7043570709.pdfIn PDF document text
    • https://frigosztufi.ro/ckfinder/userfiles/files/46178039310.pdfIn PDF document text
    • http://longruiglass.com/ckfinder/userfiles/files/20210917_015716.pdfIn PDF document text
    • https://next-engineering.com/userfiles/files/29484944448.pdfIn PDF document text
    • https://huaku3c.tw/uploads/files/202109140342306040.pdfIn PDF document text
    • http://cabini.it/userfiles/files/39678763052.pdfIn PDF document text
    • http://gimhaejazz.com/fckeditor/userfiles/image/87047371767.pdfIn PDF document text
    • http://ddservice-bmw.pl/userfiles/file/wixugaxun.pdfIn PDF document text
    • https://ismet.com.br/ckfinder/userfiles/files/xikizutekore.pdfIn PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/5baf9f6126d861fb229299e744cba469/25444510441.pdfIn PDF document text
    • http://westernstudioservice.com/admin/userfiles/file/tilamedeluf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=home+workout+no+equipment+premium+quality+mod+apkPDF 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_off0000b360.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB360 10912 bytes
SHA-256: f4a493354123bb30cfca806d9b824c292477efceea92928bba5fdd12357c4feb
font_01_sfnt_off0000cc5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC5E 17576 bytes
SHA-256: 298b49adc0a99f80069c3bf80c3e681551190eb03be57848642d143887aa8785
font_02_sfnt_off0000f97d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF97D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1