Malicious PDF — malware analysis report

Static analysis result for SHA-256 d83be9c00bfff82b…

MALICIOUS

PDF

70.1 KB Created: 2021-09-17 00:13:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d90c37651ec84da5cc5d19f4f5c4894d SHA-1: 4816a2b39590dda2a4a35843b18eb26757bd9ea0 SHA-256: d83be9c00bfff82bdcca59d2dc0ab1ae86969047d2b3b0d948e3fab23083886e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which are associated with compromised CMS uploads or are part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

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://crysiq.ru/uplcv?utm_term=difference+between+independent+t+test+and+paired PDF link annotation
    • http://tumwebthailand.com/ckfinder/userfiles/files/xabepuxilobojinekibof.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613a901dc3e5a---wodexinakav.pdfIn PDF document text
    • https://balajitutorial.com/admin/userfiles/file/xabagunap.pdfIn PDF document text
    • http://h-n-s.net/userfiles/file/8967868151.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/18455427830.pdfIn PDF document text
    • http://casavacanzesanvito.eu/userfiles/files/jeporewide.pdfIn PDF document text
    • http://orderkai.com/uploads/files/saxawukosibawenuzijari.pdfIn PDF document text
    • https://georeno.ca/userfiles/files/90110286059.pdfIn PDF document text
    • http://chapaconoticias.com/assets/ckfinder/core/connector/php/uploads/files/70874128068.pdfIn PDF document text
    • https://studybrilliant.online/app/webroot/img/userfiles/file/panusovetiseriluv.pdfIn PDF document text
    • http://indianmailbox.com/assets/images/userfiles/files/6714408231.pdfIn PDF document text
    • https://cottonweb.net/userfiles/file/laberavesatove.pdfIn PDF document text
    • https://daulte.ch/ckfinder/userfiles/files/28147746688.pdfIn PDF document text
    • http://adamex.ukrkarta.ua/fckeditor/userfiles/file/matusalixigenopo.pdfIn PDF document text
    • http://www.alexgis.com/siteuploads/editorimg/file/998208658.pdfIn PDF document text
    • http://www.rpv-drachten.nl/files/file/96080485993.pdfIn PDF document text
    • http://finemetal-cn.com/upload/files/30191412492.pdfIn PDF document text
    • http://driscollandgibson.com/images/edit_images/file/lagedutigojuxul.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/79182351040.pdfIn PDF document text
    • http://congluc.com/upload/files/89037099892.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1612f3de7466bb---3851173736.pdfIn PDF document text
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/57a95c59bbaee8b1f09fac0815f41a87/jodimutulozudikosufepe.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_off0000b42d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB42D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC44 10676 bytes
SHA-256: 70b1f2ba80c806fc8473e3a0de6cb665ad982bff0ce107b0e6a9e6e976ebba95
font_02_sfnt_off0000e4bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4BD 14968 bytes
SHA-256: 4979ef563cb1f59363c97ada17050a2c4f184b43ea5e0149bbb29e0cf1373a9e