Malicious PDF — malware analysis report

Static analysis result for SHA-256 bcff53b3bb4b2eff…

MALICIOUS

PDF

75.4 KB Created: 2021-09-03 18:04:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 9b6e2cc87c3229bbb429d9a1687d23f1 SHA-1: 3c5819902bbe69394a556a20be24b12e38e0ebae SHA-256: bcff53b3bb4b2eff6cf61fa2210e3371c47b8e89d5a1154e9b5be4dfb32d22a8
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The file's metadata indicates it was generated by wkhtmltopdf, a tool often used to create PDFs from web content, further supporting the idea that it's a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 https://queure.ru/uplcv?utm_term=trigliceridos+altos+en+ni%C3%B1os+pdf PDF link annotation
    • http://herculesestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/17528992188.pdfIn PDF document text
    • http://leebyunghun.kr/new/upload/board/files/duriguwitogadulekek.pdfIn PDF document text
    • https://mujeresenmovimientoplus.com/userfiles/file/65146275181.pdfIn PDF document text
    • https://casalindasbakery.com/ckfinder/userfiles/files/vuxibona.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608d0c00a6599---96801339265.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1610b52bb1917d---fironobetene.pdfIn PDF document text
    • http://ottotech.center/userfiles/file/joruv.pdfIn PDF document text
    • http://jfe.hk/userfiles/94058876390.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160bc3e9fa5256---6436466518.pdfIn PDF document text
    • http://clinicaveterinariasangiacomo.it/userfiles/files/27531989536.pdfIn PDF document text
    • http://wib24-admin.de/uploads/file/84200790419.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e74bd30671a---pudapon.pdfIn PDF document text
    • http://andrenickels.de/ckfinder/userfiles/files/37300586579.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d4ad5986e62---gunovozoburegonumu.pdfIn PDF document text
    • http://budgettranslation.hu/sites/default/files/file/disonabufamonibukeguvivob.pdfIn PDF document text
    • https://betentour.com/sites/default/files/file/74186137842.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/82863c3f6b3b37ae8c007a47a7c02111/80066876242.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/9b567a4649ebaf8ecaf95dde557cf960/96669661544.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/502vdmul73d7a4onld9f0u1rgp/tofekelogiwil.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/161000d543e2b5---sufigajekaxe.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091aaf407b74---mukesonozuvomefurad.pdfIn PDF document text
    • http://learnersdigest.org/userfiles/file/powusoxigiz.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/1642e15fa8622a1e6a072510bdb79785/37015380251.pdfIn PDF document text
    • http://hawks79.com/clients/85064/File/93362286073.pdfIn PDF document text
    • http://ohadalegistrocbarter.com/ckeditor/uploads/files/tajexasarebopikefetawu.pdfIn PDF document text
    • 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_off0000c15e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC15E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d975.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD975 10964 bytes
SHA-256: 1b5ebe4280481d2c5c9fc1960c0283c4c03407f78379f46f90fd5593bc8276db
font_02_sfnt_off0000f288.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF288 17416 bytes
SHA-256: 22ce82d05907e229b0165f22d09615391bd32917c29e8f8b0df67334b2f7f6c6