Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c13420a1cc5f8d7…

MALICIOUS

PDF

89.0 KB Created: 2021-07-20 18:50:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 40a6242c3b620ed7b7f6d712789851c9 SHA-1: 5e3b4d2b50a7fd32bda2967d3a139562acfc7867 SHA-256: 1c13420a1cc5f8d76001f88c3fe93ec674415e66feef40c351685fac5903d478
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links to external PDF files hosted on various domains, many of which appear to be compromised or disposable. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of a link farm on compromised CMS upload storage suggests an attempt to obscure the true destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://hissekurban.com/resimler/files/lizenofanuxanizomokisipew.pdf In PDF document text
    • http://yossy.biz/userfiles/file/jomakuxuto.pdfIn PDF document text
    • http://brooklinehs1964.com/clients/6/6a/6a3559cec3eb17f551da2d864c8c85ab/File/vutebumufufuvizonobogevu.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/bee2961b0f156c4cde1b8df46f9d8c8c/rixilapo.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-5-19/20210519171338720363.pdfIn PDF document text
    • http://novo-foto.ru/ckfinder/userfiles/files/vijatebet.pdfIn PDF document text
    • http://fapannimario.it/userfiles/files/sosunutufimiwowewav.pdfIn PDF document text
    • http://toyteepee.com/uploadfiles/file/210604045708718500zl3r7l.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c7af7cb4e98---fasunuzepuvu.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/19555ac5e934ef1c2c608ee415c4b156/damefojogaxe.pdfIn PDF document text
    • https://ajwatravel.com/wheelmarine/userfiles/file/95158965245.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/9a4lvtfmeg73kb97me66g04p2o/tuzigil.pdfIn PDF document text
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/tinemupotosozi.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/b0dde7a0684cb2a600a3f6e0939e2369/46048743067.pdfIn PDF document text
    • http://dailycan.com/userfiles/files/timadi.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/g3p3527pc7o9o6b4fodimg0gd6/padonunotoba.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160943a18768e9---92961438175.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/5dc75910aff4b2a9aac96b1a75a8a2e9/doxopawedonimewunosol.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021061815370159.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/edd2fdb02fb82dca9fd672d2b0102dc7/85967993268.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/1ac51eb8381fafc18ef583c2f613a23a/rosulomunanaweziviwi.pdfIn PDF document text
    • https://muguet.fr/sites/default/files/file/fabejakekubafesowesapelof.pdfIn PDF document text
    • https://castilloexterior.org/ckfinder/userfiles/files/bajituxe.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160980e32b9ca3---vofujez.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/65029014725.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=a+short+account+of+the+destruction+of+the+indies+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_off0000f768.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF768 10752 bytes
SHA-256: 849072040250b278b8d71a64e3ee1c0975e10e21e52ff84a0242f28443392de5
font_01_sfnt_off00011025.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11025 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012837.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12837 16992 bytes
SHA-256: 920f8602f676f49eb178e1188f7b1aa6ba58e1ece0a05ebbea01dfe83de4df34