Malicious PDF — malware analysis report

Static analysis result for SHA-256 52fc4453c810949d…

MALICIOUS

PDF

75.0 KB Created: 2021-07-04 01:52:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 52d3e647c839ab629f31520c5c830251 SHA-1: 8e05c3078f5649799a4e7a79c272d84dbb38f70a SHA-256: 52fc4453c810949d3e50794c1b844ce65a0c4f6a9bdd5c58c30929034750959c
176 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to compromised websites hosting further malicious PDFs. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user consumption but rather as a vehicle for the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/d8d11e87fae204bfe88d14f1f13d2fda/jowosuwufelujoj.pdf In PDF document text
    • https://www.escon.it/wp-content/plugins/super-forms/uploads/php/files/ffe3f3fa45981f3f27cbc5739503691a/mebesulilanorerazizija.pdfIn PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/1btsdh8tnnfeq2fs0q82d735is/xaxijatokexefaxo.pdfIn PDF document text
    • http://mywayrtk.info/userfiles/file/19252882356.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/96b201fa7920cb16feba1da2ca3bcdb9/7613307815.pdfIn PDF document text
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/ak1upo8e5ra5e5unh9n1jphan5/48258132041.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607d545f17f07---kojenikikipemifabuzonix.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7536f29f27---zarizekalax.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/lpqpnsf82qmt0bi5b7ioni925v/zikonidegobisusufowi.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ec1bcd91b7---23747843033.pdfIn PDF document text
    • http://www.gesas.it/media/mailinglist/file/daginasax.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/8sfc96ev88a41dk07sijt5opun/36508496372.pdfIn PDF document text
    • https://www.picmephotoboothhire.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160759e6bd737f---disoxup.pdfIn PDF document text
    • https://ventadeterrenosurbanos.com/userfiles/file/29977891562.pdfIn PDF document text
    • http://lab4050.com/upload/editor/file/fezol.pdfIn PDF document text
    • https://motoquadro.de/userfiles/file/xifevibumimolifanulo.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/f77f6c44eff4e12e138f6929c0e4bbbd/43245157497.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/16074f8d2456cd---49880530308.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095b2f2853dc---gelek.pdfIn PDF document text
    • http://shreyaghoshal.com/konadnew/userfiles/file/89492268368.pdfIn PDF document text
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/c63cc1d1a8cffc9756428388983d1659/18067976175.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/f47922639155dd0b6b937307d6bfaee4/34676309781.pdfIn PDF document text
    • http://pampa.be/uploads/userfiles/files/68270370627.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4ab9de050---91620046818.pdfIn PDF document text
    • http://barrybusiness-crm.com/ressource/devis-photo/files/38446399918.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=understanding+construction+drawings+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_off0000bf28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF28 10944 bytes
SHA-256: 0e42ddf838f1348fa7d13b3c4313243d0c14e7fb1b08cb1a90bfb15382b7cd90
font_01_sfnt_off0000d883.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD883 18264 bytes
SHA-256: fe14fe2b26906612cb9191af25cb939eb8a7d6d22aef9ab0516941ae19365569
font_02_sfnt_off000106a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1