Malicious PDF — malware analysis report

Static analysis result for SHA-256 55d9397a404befa3…

MALICIOUS

PDF

80.6 KB Created: 2021-09-16 22:59:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c431356f847a153d9788e50dfe6e4ccd SHA-1: 01089d8765f2e86fa0c1e888c595f6d5939ad7e5 SHA-256: 55d9397a404befa3e6bf7d45e926a39d31f6c4a2d4f6347068f5aacf18de28e9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The file contains numerous embedded URLs pointing to compromised CMS upload storage and disposable hosting, suggesting it functions as a link farm to distribute phishing content or further malware. No scripts were extracted from this sample, but the presence of external URIs and the link farm structure strongly indicate a malicious intent to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://pistant.ru/uplcv?utm_term=marvel+contest+of+champions+hacks PDF link annotation
    • http://vinhthuanvietnam.com/upload/files/85899534375.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ff8b8b31b7---zapazinonovepab.pdfIn PDF document text
    • https://chaletsuenodesol.de/files/12669600515.pdfIn PDF document text
    • https://4of100churchstreet.com/assets/media/files/3703500206.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613d4b1ea22cf---lapajejojo.pdfIn PDF document text
    • https://kham.vn/userfiles/file/zikazu.pdfIn PDF document text
    • http://www.ctnphrae.com/ckfinder/userfiles/files/56428211058.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161319ced4c75b---52308778928.pdfIn PDF document text
    • https://trade.inter-ural.ru/ckfinder/userfiles/files/35217132832.pdfIn PDF document text
    • http://costruzionibulagna.it/userfiles/files/80467348179.pdfIn PDF document text
    • http://kleinschadenexpert.com/userfiles/file/zixara.pdfIn PDF document text
    • http://movitecnic.com/ressource/site-image/files/93042148897.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614249bde7125---majukidafuwi.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141bd0b994c0---9347115668.pdfIn PDF document text
    • http://harc-ias.vn/Images_upload/files/zubasufilasel.pdfIn PDF document text
    • http://dmhu.eu/uploads/uplib/file/92756825958.pdfIn PDF document text
    • http://de.ruben.pl/ckfinder/userfiles/files/bogezoxulominepokum.pdfIn PDF document text
    • https://mimpishio1bet.com/contents/files/28679287477.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1613aa748e3bb4---betokabopufiw.pdfIn PDF document text
    • http://www.tamtrebinhminh.com/public/files/15239843467.pdfIn PDF document text
    • http://ityab.com/cache/fck_files/file/28228042037.pdfIn PDF document text
    • http://psystems.gr/Administrator/uploads/userpics/OutPostImages/files/tolijisixivo.pdfIn PDF document text
    • http://swaptoys.org/ckeditor/uploads/files/27334271927.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_off0000cebf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEBF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6D1 20224 bytes
SHA-256: 787c48ef6b6013444f6b98b2008872991335883b1f46f3acf89239ab742b1641
font_02_sfnt_off00011b9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B9B 10896 bytes
SHA-256: 29146a869fd00e1bcfed472378574bb607516da94fe346c4bf0534bafa06d835

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