Malicious PDF — malware analysis report

Static analysis result for SHA-256 593c8b36f6af3619…

MALICIOUS

PDF

88.1 KB Created: 2021-09-12 12:27:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 186749f6c4e3cf31377e2d279948dea8 SHA-1: 26cc7be643ef3bd0e6a7fb82ee7ed5ee36d952e3 SHA-256: 593c8b36f6af36190c82d15d41925e2fe347255040fd6ded1f2b6ff236a4230f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. It also features a link farm pointing to multiple distinct hosts, with several URLs hosted on compromised WordPress upload storage, suggesting an attempt to obscure the final destination. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://dianacb.cz/userfiles/file/24574876454.pdf In PDF document text
    • https://felicitareonline.ro/ckfinder/userfiles/files/sekutejiva.pdfIn PDF document text
    • http://nathulaldasptti.com/ckeditor/ckfinder/userfiles/files/19276722102.pdfIn PDF document text
    • http://jeansresource.com/js/ckfinder/userfiles/files/suwebuborufigojajozu.pdfIn PDF document text
    • http://hillsclinic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/7435199470.pdfIn PDF document text
    • http://nuklearmedizin-amro.de/userfiles/file/xusigokaja.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/7219472714.pdfIn PDF document text
    • http://ydyb.com/filespath/files/20210911084637.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161342fc01c816---pewuz.pdfIn PDF document text
    • https://kimcert.org/E/file/balifegilufikazube.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613a0590e802d---wajodivepuguzi.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///76769970775.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/d81242829c242f34dea50b17be21d6e5/5826175383.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/16136950b53781---sopetila.pdfIn PDF document text
    • http://2990592.ru/ckfinder/userfiles/files/40814577767.pdfIn PDF document text
    • http://ros-audit.com/i/up/file/dotezopolomefej.pdfIn PDF document text
    • http://mrukseo.pl/userfiles/file/63941138024.pdfIn PDF document text
    • http://vcelari.naceradec.cz/includes/ckfinder/userfiles/files/toviwoluvafonota.pdfIn PDF document text
    • https://nepaltrekkinginhimalaya.com/assets/userfiles/files/28712051085.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/16428859533.pdfIn PDF document text
    • http://ohmytour.kr/FileData/ckfinder/files/20210910_A40652A744EB706D.pdfIn PDF document text
    • http://sanyosushiglendora.com/uploads/files/85807700181.pdfIn PDF document text
    • https://webmakler.org/userfiles/file/80558578877.pdfIn PDF document text
    • http://myredm.ru/uploads/file/68607652330.pdfIn PDF document text
    • http://xn--z92bzy85x.com/userData/board/file/84215210236.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161378ac9d39a6---8350920535.pdfIn PDF document text
    • http://ap116.ru/userfiles/file/podivodejogibazi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=tamil+play+com+kgf+full+movie+downloadPDF 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_off0000f1ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000109ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109FF 17688 bytes
SHA-256: d85d9664dc8bd296d6e7e0146c996db503ea7896359078ad36839e487e116e8d
font_02_sfnt_off0001383c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1383C 11020 bytes
SHA-256: 764f237d5f746301ea18f5549d32d94a0f8f0ce8c680fbc1a66645ef8f6bb872