Malicious PDF — malware analysis report

Static analysis result for SHA-256 951bd36b915cc943…

MALICIOUS

PDF

77.2 KB Created: 2021-09-14 12:11:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: be3956dbe864778a95b50d14d360e74c SHA-1: 1c90a5dc76bcc9e227d8e0cffc7309094b6317f7 SHA-256: 951bd36b915cc943289d8da71d171684e49d7bd9869df0fcc231860ce1916feb
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. Heuristics identified it as a link farm on disposable hosting, with numerous external URIs pointing to other PDF files. The document body is heavily obfuscated, but the presence of embedded URLs and the overall structure suggest an attempt to distribute further malicious content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://pistant.ru/uplcv?utm_term=las+siete+tragedias+de+sofocles+pdf PDF link annotation
    • http://xn--90aoj0agf7cq.xn--p1ai/uploads/files/52912954720.pdfIn PDF document text
    • https://getracemirates.com/userfiles/files/97918326272.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1613c1ec7287f0---70994093183.pdfIn PDF document text
    • http://spad.kr/userData/ebizro_board/file/jipeweramitilowavudubo.pdfIn PDF document text
    • http://orthopaede4you.de/userfiles/file/80772521565.pdfIn PDF document text
    • http://corporatiegids.nl/uploads/files/rekebowuvowiseladegovu.pdfIn PDF document text
    • http://pegastelco.com/pictures/files/54432846648.pdfIn PDF document text
    • http://uniquehotelsolutions.com/files/others/punikinogolufawajawon.pdfIn PDF document text
    • http://risorsaterra.it/userfiles/files/27789785578.pdfIn PDF document text
    • https://idea-web.ro/app/webroot/files/userfiles/files/xadozefibuvopon.pdfIn PDF document text
    • http://auto4-spb.ru/public/images/ckfinder/files/wezeromos.pdfIn PDF document text
    • http://worshipedia.mobi/sites/default/files/file/litabibedevupilelulil.pdfIn PDF document text
    • https://www.greenlakecruises.com/ckfinder/userfiles/files/vibakoka.pdfIn PDF document text
    • http://adec-interiors.net/Uploads/file/75519024640.pdfIn PDF document text
    • https://tekstilkentrehber.com/upload/ckfinder/files/78911839970.pdfIn PDF document text
    • https://profix.fr/ckfinder/userfiles/files/41872009105.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/48246333421.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/biragivil.pdfIn PDF document text
    • http://kuresi-kaitori.com/upload/content_pic/files/naseviwigi.pdfIn PDF document text
    • https://ukmriptek.org/codeIgniter-hmvc/userfiles/files/mivowixonivelaxidi.pdfIn PDF document text
    • http://handsonmontessoripk.com/userfiles/files/gopumirarivawojiko.pdfIn PDF document text
    • https://artlabjo.com/userfiles/file/vevelatufemojotoka.pdfIn PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/79338127269.pdfIn PDF document text
    • https://nationalshield-uae.com/userfiles/files/kibole.pdfIn PDF document text
    • http://vuatoyen.com/uploads/userfiles/file/silurime.pdfIn PDF document text
    • https://rolcsi-bau.hu/userfiles/files/80027704707.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_off0000c854.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC854 17908 bytes
SHA-256: deecd713d976d8c3a90dc151101da9c0168d4a108fee345f06b039112ed722b9
font_01_sfnt_off0000f648.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF648 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E5F 10648 bytes
SHA-256: dad86f65a6793d0027ded170688d4bf6b03e74f57c93616a5275e831c0135b9b