Malicious PDF — malware analysis report

Static analysis result for SHA-256 40e90dc751acc8ce…

MALICIOUS

PDF

88.8 KB Created: 2021-09-01 01:58:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 0048d83305ba5367bac5788591c1eb69 SHA-1: 5cc84b08c4c5d0c6dafce57bf0bf060440ebab57 SHA-256: 40e90dc751acc8ce28597dbe1701a2575017690e281b35db4c192e76f6ab6ef0
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content to analyze.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://drafthe.ru/uplcv?utm_term=anastrophe+in+poetry PDF link annotation
    • http://alpha-th.com/userfiles/file/2198175061.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b25822db1e5---pufofo.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/i36gm8u8cu4kah16agsas3he04/86758017329.pdfIn PDF document text
    • https://nhahangthanghuong.com/uploads/files/58404790721.pdfIn PDF document text
    • http://the100voicesofgospel.de/fichiers/newsletter/file/57134805744.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b31e7296997---fugonunaloxabukazudulaj.pdfIn PDF document text
    • https://www.marvistasales.com/wp-content/plugins/super-forms/uploads/php/files/69030170357fccab8b26aadc07cae20e/tiwasavugivixesomonigikub.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160864b0cc7c11---18973161579.pdfIn PDF document text
    • http://opalsolar.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160771794e4acd---41718526660.pdfIn PDF document text
    • http://kameleonhastanc.hu/files/file/46221768308.pdfIn PDF document text
    • http://sghscsjamarai.org/guruhargobind/userfiles/file/25584371388.pdfIn PDF document text
    • http://bebelino.ru/userfiles/file/82104159583.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082c5a12cf65---digukipo.pdfIn PDF document text
    • http://getvisa.ru/images/File/sujironegaxeroxuga.pdfIn PDF document text
    • http://sl-light.ru/design/img/upload/file/savitutejesusova.pdfIn PDF document text
    • http://ngocphuocjsc.com/public/default/ckeditor/files/tabisijamufam.pdfIn PDF document text
    • http://imaginove.eu/data/Files/letokugirijazonej.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/b4dda0da1bc9674e320cc85f65feaa8e/zodulu.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/a11ee2ec8b6be85d10d60de19475f168/49718911930.pdfIn PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/39135593753.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/m4m0irk3248murt1kj37br5llj/simabifojezetudezonemagin.pdfIn PDF document text
    • http://iswii.net/ckfinder/userfiles/files/zosolepenirobipa.pdfIn PDF document text
    • http://mebelhotel.ru/userfiles/files/39260022079.pdfIn PDF document text
    • http://ray-king67reunion.com/clients/41562/File/ravigunuzena.pdfIn PDF document text
    • https://mahae.hu/files/files/kajozebobafowubap.pdfIn PDF document text
    • https://strategieb2b.com/userfiles/file/pirekitagojafubasu.pdfIn PDF document text
    • http://fitviewer.biz/files/file/49352070233.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_off0000f455.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF455 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010c6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C6C 10400 bytes
SHA-256: 683fdf1a312324f4435444bb913e29fe1e2aa0c3908e15fcd51aacdf63d52083
font_02_sfnt_off000123f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123F8 19080 bytes
SHA-256: b7f61608f797d8d5e7128325d866ac3c0cacca14c904253080b5e3fbba43ad5d