Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b4a92e00eb87e8e…

MALICIOUS

PDF

86.9 KB Created: 2021-10-06 01:59:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: cbcd65d1b4a6c92ec14efc1243653f85 SHA-1: 86248fe44e6e39e3e5a69511051ca4a01601e830 SHA-256: 4b4a92e00eb87e8ecc11ce76cef58cd70b16969f28a1a530ad5baddd796bfac6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. The heuristics indicate the PDF acts as a link farm, directing users to compromised WordPress sites and potentially disposable hosting domains. The presence of external URIs and the nature of the detected heuristics suggest a phishing or malware distribution attempt, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://oniceh.ru/uplcv?utm_term=fire+mage+talents+classic+wow PDF link annotation
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files/19014729405.pdfIn PDF document text
    • http://landonintergroup.com/ckfinder/userfiles/files/52722354918.pdfIn PDF document text
    • http://www.lukoilmarine.com/ckfinder/userfiles/files/pojerobemizatepegokopu.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/qnh7vt98b6q527ch3vtskng9e7/nizejutotig.pdfIn PDF document text
    • https://elsadaulte.com/ckfinder/userfiles/files/47348593312.pdfIn PDF document text
    • http://www.itidharamshala.in/images/uploads/files/fubesazilo.pdfIn PDF document text
    • http://theemasternetworker.com/ckfinder/userfiles/files/riluruzijupam.pdfIn PDF document text
    • http://csc0512.com/userfiles/file/20210916024652_h0o66k.pdfIn PDF document text
    • https://cfacgroup.com/uploads/FCK_files/file/85475292788.pdfIn PDF document text
    • http://dylogistics.com/userData/board/file/benunanurisawa.pdfIn PDF document text
    • https://cruiseship.cruises/wp-content/plugins/super-forms/uploads/php/files/4oh7kiqonrm7ovuug7ki8i4pnk/risobenujopisiropu.pdfIn PDF document text
    • http://ledseoul.com/userData/board/file/15204319278.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/vagulirojejodozofusomakus.pdfIn PDF document text
    • http://xn--80aafmoni2biho.xn--p1ai/admin/ckfinder/userfiles/files/xawes.pdfIn PDF document text
    • http://mizuho-co.net/file/ck/files/detewesiwudax.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/4decb5474f0a8ba472c46e2b3fffd7ba/buvudirezisemisa.pdfIn PDF document text
    • http://studioindelicato.com/userfiles/files/basitatemonotamivobev.pdfIn PDF document text
    • https://dunakanyarfesto.hu/ckfinder/userfiles/files/rafedosojefuj.pdfIn PDF document text
    • http://minuspk.ru/minuspk.ru/userfiles/file/bulapixajide.pdfIn PDF document text
    • http://handsonmontessoripk.com/userfiles/files/famepubesanozosu.pdfIn PDF document text
    • https://ubranni.com/uploader/files/dijavu.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_off0000f05f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF05F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010871.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10871 17400 bytes
SHA-256: 378825762f61eedf4ab8aafaee7376d63eba821f0603ae8ece1444d82a9d5ce1
font_02_sfnt_off000135b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135B3 10636 bytes
SHA-256: 39ecc18c3c127d382df9da22090270fb7923620ac508a77f099c1fe3e444de84