Malicious PDF — malware analysis report

Static analysis result for SHA-256 351629ea820e55e0…

MALICIOUS

PDF

87.9 KB Created: 2021-08-03 11:51:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a941be5c5e01c572b115a1a03db222e8 SHA-1: de30f8515921385adcc141fde6c664c84343ee2a SHA-256: 351629ea820e55e00ea3c20e95369507c88bd4ff2cbfa2fbc9af43cf1aceca83
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised CMS upload storage and disposable hosting, suggesting it acts as a link farm to redirect users to malicious sites. The PDF structure and link farm characteristics are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/1225da864252f38f7868b63b23b5a99e/47275093748.pdf In PDF document text
    • https://www.zulilighting.com/wp-content/plugins/super-forms/uploads/php/files/3d68454eab71b5d1453e312ccd49fbec/17227175959.pdfIn PDF document text
    • http://mega-treid.com/userfiles/files/wetenoxuzipawizomomes.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/6289a339b84aa336195123b318741d88/bevuwovuvilenogarogatoxu.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/160a37379b4bc2---41966363666.pdfIn PDF document text
    • http://bellina.pl/userfiles/file/72446847469.pdfIn PDF document text
    • http://meble-tk.pl/userfiles/file/meduzarofemevujijumov.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607f41695f6db---vupowepilubeviwugasovuma.pdfIn PDF document text
    • https://ntpuvoice.com/ckfinder/userfiles/files/fogugi.pdfIn PDF document text
    • http://limobebe.com/userfiles/files/15525086334.pdfIn PDF document text
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085872f245ff---bupunodozuwuveximububi.pdfIn PDF document text
    • https://ceccargiurgiu.ro/userfiles/file/nodopoxef.pdfIn PDF document text
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fdf828b34c---42073469762.pdfIn PDF document text
    • https://rockyshairsalon.com/wp-content/plugins/super-forms/uploads/php/files/auk5l7ai22im44u4eotvjl28jo/55429856180.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d5aaac364da---wabusibag.pdfIn PDF document text
    • http://geobrofab.com/clients/d/da/da7cd3953015cd63472398095fc1fcdd/File/20423427553.pdfIn PDF document text
    • https://www.studiorosaliabusco.it/ckfinder/userfiles/files/32022714934.pdfIn PDF document text
    • https://zlatartopalovic.rs//files/viwov.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a18152bca92---42326375074.pdfIn PDF document text
    • https://akvaguru.hu/user/file/totama.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075039bd7f88---15665796838.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4165546909---jebigige.pdfIn PDF document text
    • https://tort-art.ru/userfiles/file/17619872473.pdfIn PDF document text
    • http://hyosangjo.com/userfiles/file/20210620150810.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c6b013ff61---gitewexupawozoforatiledot.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=what+makes+a+good+problem+statement+in+researchPDF 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_off0000f03e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF03E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010850.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10850 18108 bytes
SHA-256: 83c29a2e1d8c8bd503f3dd42615df23826d172ba87236c0bba77c1ca013bab1d
font_02_sfnt_off0001381b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1381B 11188 bytes
SHA-256: 6a9b6c62a76b577b3448b3118075a1edc3fb71f5db6571660dd0a69c9b188545