Malicious PDF — malware analysis report

Static analysis result for SHA-256 55f3839f64f0725d…

MALICIOUS

PDF

85.0 KB Created: 2021-07-08 11:23:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 87e8206a450d275fe7ce52a6b0822049 SHA-1: cb589839d7a4f11b565f5ac6da22326549995ce6 SHA-256: 55f3839f64f0725df8180ed5fe0e52d979da0c78a90db21ebada99c0bee2d8d8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs pointing to compromised WordPress sites, indicating a link farm or SEO poisoning attack. The ClamAV detection and ML classifier strongly suggest malicious intent, likely to redirect users to potentially harmful content or phishing sites. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document designed to lure users to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://irlanc.ru/uplcv?utm_term=2k15+apk+download+for+android
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/cq1j6nsbm81fog298ko6vqii3t/xomirip.pdf
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/0dek431acc0opufa77tfoo7927/54797456043.pdf
    • https://ajwatravel.com/wheelmarine/userfiles/file/nujikut.pdf
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/39ea48d47fb8c951124a75a4eb0dbe7b/roninuriregepefevow.pdf
    • http://agro-pasz.pl/ckfinder/userfiles/files/94467300391.pdf
    • http://houselandia.ru/files/fudasadagafenuka.pdf
    • https://gamasteel.net/userfiles/file/84221894105.pdf
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076bae9c5b1d---39122679980.pdf
    • https://www.icslights.com/wp-content/plugins/super-forms/uploads/php/files/3072a6f77817b489e842787a420674c5/52310632167.pdf
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160836e7f7a701---gelosagexapasilukakaves.pdf
    • http://kolesnikov.pro/ckfinder/userfiles/files/xozakimunisozinomofevo.pdf
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160717c2588634---97634621210.pdf
    • https://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/a6b17a0651fc505944421d4603704a78/98122193857.pdf
    • http://msslink.ru/userfiles/files/takubedufudoj.pdf
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/feb36dd2b85c1d6e02237198a9662935/38087025253.pdf
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608640b6dfa07---woluxazuvijoxewabare.pdf
    • http://synthecinter.com/userfiles/files/81214622234.pdf
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609cdc34a1f46---porawu.pdf
    • http://cuatro-pr.org/sites/default/files/file/bosajo.pdf
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b82bac78d96---rowegesikatikuze.pdf
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/4c1f58509e0c891b53f2461f4de0f832/10002937866.pdf
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b4925b1157e---kefofetosimaniruzej.pdf
    • http://abaj.cz/UserFiles/File/15331926507.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea43.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA43 16792 bytes
font_01_sfnt_off0001025a.bin
e1275a2c2139e4562b54a6d3b79773eecd6f25f8dd00cadc1de72693e1eadc76
pdf-font-stream PDF embedded font (sfnt) at offset 0x1025A 10480 bytes
font_02_sfnt_off00011a55.bin
1a8157f3cf29303e519f86d2bbb56c7acbd0182f9f09b791d36a6bf970b6f1f0
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A55 17092 bytes