Malicious PDF — malware analysis report

Static analysis result for SHA-256 c61bf6b28a9c307a…

MALICIOUS

PDF

80.4 KB Created: 2021-08-27 18:24:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: cd512b4c33302b2d5a7a48d81c95dfbd SHA-1: 806cde898ee24a28dd5452df16dfa487173d126c SHA-256: c61bf6b28a9c307ae372cdcb0e29b714106bbbf294d7096feb8057843937641f
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple domains, several of which are associated with compromised CMS uploads or disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the presence of numerous external links is the primary indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://ort168.com/upload//ckeditor/files/kepivufoduvujisejibijo.pdf In PDF document text
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a216f4adf2d---19936592240.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a790d2bb1a6---minasifaxobu.pdfIn PDF document text
    • http://svb-volleyball.de/userfiles/file/numajoledetafu.pdfIn PDF document text
    • http://zulassungsservice4you.de/bilder/file/63576380348.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606ced747cd58---ganibaxapugotarome.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/160be54d835b1e---xisatadafafozeguxopibus.pdfIn PDF document text
    • http://chromatographvials.com/d/files/tadepefafiw.pdfIn PDF document text
    • http://1yunnan.com/ckfinder/userfiles/files/42116408079.pdfIn PDF document text
    • http://www.petercar0937494634.com/upload/img/files/37611740468.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16118a9088eb04---buxuvubixavule.pdfIn PDF document text
    • https://deltagroup.bg/uploads/file/31220916601.pdfIn PDF document text
    • http://www.w.radeton.cz/ckfinder/userfiles/files/89049856376.pdfIn PDF document text
    • http://harasim.cz/uploaded/files/sivefudokaxozu.pdfIn PDF document text
    • http://md-servicios.com/userfiles/file/2853168468.pdfIn PDF document text
    • https://gadd-asso.org/userfiles/file/84751657623.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/16080444f74df7---76534725585.pdfIn PDF document text
    • https://mogilew.ru/userfiles/file/95225264854.pdfIn PDF document text
    • http://fujiya-la.com/uploads/files/fufibujofile.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/gunos.pdfIn PDF document text
    • https://mirrorlink.com/public/files/files/32677578481.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/52937651225.pdfIn PDF document text
    • http://gramercygrand.ru/files/file/62568998601.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=the+call+of+cthulhu+1928PDF 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_off0000d4ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4ED 17832 bytes
SHA-256: 30c247dcb4a45f52b6e4b1b1e541917e5b6bfb39eb191b23d3c752bdf7e7f2a8
font_01_sfnt_off000103b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011bc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BC9 10580 bytes
SHA-256: 633bc82ac98d9116d5ca7da8cc5fd7157e9bf4e5e3961e29a42631a12b93fb6c

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