Malicious PDF — malware analysis report

Static analysis result for SHA-256 8997b7dd4b343c22…

MALICIOUS

PDF

71.5 KB Created: 2021-09-11 12:49:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 89769d770841e81f9cd0e2ae7e57a1bb SHA-1: 9fe78c0b61dea9a658e313eada622cc35a40f550 SHA-256: 8997b7dd4b343c22a2841932cb5be1f48b9518bc89e6adafd4ece7877203c58a
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm or SEO poisoning attempt. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, but the structure and URL analysis point to a malicious document designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 http://mzch.pl/userfiles/file/50777904665.pdf In PDF document text
    • https://fond.ru/userfiles/file/fosevekefuzuredugu.pdfIn PDF document text
    • https://postelezmasivu-praha.cz/ckfinder/userfiles/files/xirijagoja.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/f6h9la8mdo35hbtdr7crj9h5tj/wadikefimawibibap.pdfIn PDF document text
    • http://backupcenters.com/userfiles/file/19612633905.pdfIn PDF document text
    • https://dpengineers.info/admin/userfiles/file/kavebene.pdfIn PDF document text
    • http://naturenhuman.com/app/webroot/userfiles/file/pipigavezepetidubigajar.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/1b7e2f106fc2b86bd13e9017e9e3eddc/26491548575.pdfIn PDF document text
    • http://thoitrangvabaoho.com/Images_upload/files/tewuzafenurusumumitopofuj.pdfIn PDF document text
    • https://listapp.in/ci/userfiles/files/15268750235.pdfIn PDF document text
    • https://greenbins.ca/ckfinder/userfiles/files/65192020875.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///navorojinebage.pdfIn PDF document text
    • http://perfect-aerosol.eu/userfiles/file/29457297503.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613607dfe5843---nuropo.pdfIn PDF document text
    • https://cardion.dk/gfx/fckimages/file/wadofifafuvixejagu.pdfIn PDF document text
    • http://amandamaitland.com/images/file/59423170911.pdfIn PDF document text
    • http://jedzenie365.pl/ckfinder/userfiles/files/wukunagadozap.pdfIn PDF document text
    • https://astoraccessories.com/uploads/ckfinder/files/37183160990.pdfIn PDF document text
    • http://virus-safe-zone.com/ckupload/files/91772288378.pdfIn PDF document text
    • http://www.koeru.eu/failid/file/wapafejutiruvumoz.pdfIn PDF document text
    • http://lovelyspa.net/ckfinder/userfiles/files/lidikuk.pdfIn PDF document text
    • https://newsru.md/upload/userfiles/files/19005134136.pdfIn PDF document text
    • https://tvmreza.tv/ckfinder/userfiles/files/velomup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=love+languages+questionnaire+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_off0000b637.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB637 10940 bytes
SHA-256: 7d783b5e21ac2bcd0ec09305dd7449206bda3cb369f0ae70b8b87134218ab259
font_01_sfnt_off0000cf29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF29 16080 bytes
SHA-256: 79c678afb59036d5817ec310def8dda7cffe85658d2628a15a2c9c85bb673bde
font_02_sfnt_off0000f827.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF827 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1