Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c98524c85b9df27…

MALICIOUS

PDF

76.8 KB Created: 2021-09-07 09:46:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3a0e34fafde5276568d04b59a0a0a770 SHA-1: 58be8d8937e02a822f2488e218ee86be33669866 SHA-256: 5c98524c85b9df27b71d15d47918965bf6c444241cad16a4a71d616d739b5bef
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links, many pointing to compromised CMS uploads and disposable hosting, forming a link farm designed to redirect users. The presence of embedded URLs and the nature of the link farm suggest a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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 https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/6c4e96de94cafefc08019b5704af031f/79778636690.pdf In PDF document text
    • http://svazekobciorlice.cz/userfiles/file/xusalasuresopatanojugux.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/2557f0ae4abee64c8d48abee72c11e85/diwifasekaxutimunomojo.pdfIn PDF document text
    • http://nsfeed.com/_UploadFile/Images/file/zamarudunuwinewev.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161149dfd9631a---fovufenolokokexow.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609a69da8c9bf---zavepenesumigadojin.pdfIn PDF document text
    • https://pelicanfinancialnetwork.net/ckfinder/userfiles/files/resavanulozabopavokara.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16130654b62caf---poxovifikosirijene.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a6d2ca0fca5---12752238720.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078e3fb7bebd---86943104522.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607c5e217e578---90581006526.pdfIn PDF document text
    • https://aprilboya.com/userfiles/file/zaraxejilezesa.pdfIn PDF document text
    • http://libertyquad72.fr/userfiles/file/suwawikas.pdfIn PDF document text
    • http://alteredcompta.com/buddha/ckfinder/userfiles/files/nesen.pdfIn PDF document text
    • http://kingcraftviet.com/uploads/ckfinder/files/95757220693.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b7420a1ce31---dididobunefu.pdfIn PDF document text
    • http://veterinariomauracotti.it/userfiles/files/keliniwazazinezoken.pdfIn PDF document text
    • http://maskaevlawyer.ru/userfiles/file/54636991429.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16070f12187356---9338035718.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/1609ddf49bd7fa---49062578317.pdfIn PDF document text
    • https://pernambucoimortal.com/imagens/files/55566076629.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/d6e7f162b8a58aeffc83248ec9c38a8d/zafewobozozuwokepu.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610a37e6744c0---ladobaremugivukukisi.pdfIn PDF document text
    • https://dulsuc.cl/userfiles/file/88240596242.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=vocabulary+exercises+for+high+school+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_off0000c87f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC87F 11124 bytes
SHA-256: 8a1f953153a3fcaf8c93db6b631293be492a5100f3755cd692b0448af67098df
font_01_sfnt_off0000e231.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE231 16920 bytes
SHA-256: e6a9fb26f0a161b5a1761e6d73fe7669846770372e0298a260d894fc2e6c6ebe
font_02_sfnt_off00010dab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DAB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1