Malicious PDF — malware analysis report

Static analysis result for SHA-256 7bf312b9fa4ba1c6…

MALICIOUS

PDF

84.2 KB Created: 2021-06-28 21:54:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 2c72df32404410e410b7c841f3e6ca7c SHA-1: 9fa804ceab199a442550ca548de1093d6ac5ee1f SHA-256: 7bf312b9fa4ba1c6b03db00d093e263cbca97a8a5b76d95dc1e968e4e455764e
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution scheme. The document body was unreadable due to encoding issues, but the presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest the primary purpose is to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/43cd6b9d39ba2163c996d953a5f47053/16387971510.pdf In PDF document text
    • http://alnadaoil.com/userfiles/file/61460144375.pdfIn PDF document text
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/16096dfecb308e---nularilizuvajigudod.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/ceaee18143cfca509695a32585cf76ea/demoronogiv.pdfIn PDF document text
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/vfpuh48o7g8f23civs1ml357lt/91278260863.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/51f3738fd7a4ebd84c05d36fc2b10861/86109030168.pdfIn PDF document text
    • http://dekoblickfang.de/userfiles/file/zagoli.pdfIn PDF document text
    • https://tlpnw.com/wp-content/plugins/super-forms/uploads/php/files/edef92ec8824fb6ab92a84218e15f87d/670591770.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608251d674641---37349209860.pdfIn PDF document text
    • http://ligneus.hu/upload/file/88418868773.pdfIn PDF document text
    • http://xz-brand.com/ckfinder/userfiles/files/12229660345.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/85934542472.pdfIn PDF document text
    • http://digimaap.com/wp-content/plugins/super-forms/uploads/php/files/jkgnttt7k6ad3r26i2m1s4sh3p/jutofonejupumofi.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607822bfed5bd---19240345292.pdfIn PDF document text
    • http://neodentpetrosino.it/userfiles/files/sunelivutosupaj.pdfIn PDF document text
    • http://ksnjl.com/userfiles/files/82535353188.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/93vren2f5eonbq96pfg1ehcl10/3597799692.pdfIn PDF document text
    • https://bluetact.com/locktactyuma/userfiles/file/nedisujekak.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/47145865281.pdfIn PDF document text
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/1af2dd4c4c6558a10b6febd0ccc225c7/79180390598.pdfIn PDF document text
    • http://aite-materials.com/upfiles/file/71371567021.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/nrl6o24qggfk3bnrh7tr1jcn4o/87916619159.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/e51b13297aa2be34aae20ab7881c1114/79569470687.pdfIn PDF document text
    • https://endoaccessories.com/wp-content/plugins/super-forms/uploads/php/files/4kvlvjo28p5b32k8p8ni3mpb23/besaterenokagetefa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=what+is+150ah+in+batteryPDF 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_off0000e234.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE234 17868 bytes
SHA-256: 0d6ea21871081137a6ff60d4388f66301728c8f13ecd86e4f6f3166c543e8566
font_01_sfnt_off000111a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000129bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129BD 10596 bytes
SHA-256: f7d482aa901cae39b8681e02b8f15a22daea8c677cfb7ebe0414feb26d6186c1