Malicious PDF — malware analysis report

Static analysis result for SHA-256 6d82f5726f183a2c…

MALICIOUS

PDF

88.1 KB Created: 2021-07-28 07:20:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: d0cc34fd2d1cbe8d750ad85899b7f5ad SHA-1: 50ba9632267c447a0954b141c69453600a0e46a0 SHA-256: 6d82f5726f183a2cfd3b2ddd89321312b3fe452cf2e2927ba8d64f3483d24555
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users. Although no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it may exploit PDF vulnerabilities or employ embedded JavaScript to facilitate the redirection to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/1607da1ce8836d---20333342635.pdf In PDF document text
    • http://bakoca.hu/files/file/siwobesidumavaropokokefu.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a5a02f51325---vukanadivadug.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ada3a1c4064---katev.pdfIn PDF document text
    • https://living-stone.lu/userfiles/files/7251256193.pdfIn PDF document text
    • http://dulichgiahy.com/upload/file/wuzil.pdfIn PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/71052028936.pdfIn PDF document text
    • http://stilistspb.online/public/files/uploads/files/20277112712.pdfIn PDF document text
    • http://allaboutdowney.com/userimages/90590991884.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16098235e42630---bofinap.pdfIn PDF document text
    • http://www.anjhimayath.com/upload/file/72564172653.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7ee01ecee3---zezikow.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c23958d7a0c---vulidobizorenozukimo.pdfIn PDF document text
    • http://se-ty.ru/uploads/userfiles/file/laninebo.pdfIn PDF document text
    • http://daindnc.com/fckeditor/userfiles/file/3798688060.pdfIn PDF document text
    • http://cnzhongkui.com/fckeditor/editor/filemanager/connectors/php/uploads/file/100101417194.pdfIn PDF document text
    • http://vncdata.net/app/webroot/uploads/files/pijilazodomutirugerojabo.pdfIn PDF document text
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/opc6qdn7hk894c5se3ts7n5p4o/bititolatojujifavuma.pdfIn PDF document text
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160dfbd1655b74---wofilefajamuru.pdfIn PDF document text
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/d69fd9a759d7e288e66f3313cd27f32b/34694393564.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d353f0b9bd---pafijatutogilexakekojas.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/2630m7jaoebsut6ukpiru0hk5v/84477931845.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160a3c91bc3c3b---fegov.pdfIn PDF document text
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/ip54bgt6l9dpvjs4qfl5mrs7o2/guvebilireto.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=shoo+fly+sheet+music+free+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_off0000f3fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3FD 10908 bytes
SHA-256: 3823a8185f4933aef26a6efee3f38d7b4650683b10ae6392b584ebec5e6173f3
font_01_sfnt_off00010d41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D41 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012553.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12553 17096 bytes
SHA-256: cc112eef3eaeb829559ef6e9685c21dab7f0939e59cb3435adf20e5e01f7eefe