Malicious PDF — malware analysis report

Static analysis result for SHA-256 3dc92e13f7f02b4c…

MALICIOUS

PDF

78.9 KB Created: 2021-06-20 06:26:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 66e5fbba13799800f459b6c083ee4ee9 SHA-1: e55a7b274e35e252e6ab7faeaa112a18dca075a5 SHA-256: 3dc92e13f7f02b4c1b9ff54c709f396f5f4f5d1632d5104fec98a2d137294a94
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded links pointing to various domains, many of which appear to be compromised WordPress sites used for hosting malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, but the primary malicious activity is driven by the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://chcial.ru/uplcv?utm_term=lord+of+the+rings+fellowship+streaming PDF link annotation
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/7025fppj25illmqb4onmhpk24b/21022109033.pdfIn PDF document text
    • https://haysalon.com/public_html/userfiles/file/49583022019.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/8b73a8d518c813e7564d53bb0ee973f2/31214050586.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bfa5ad6589---tigafa.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a83a3b48b05---73855135766.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607f893f96d64---15841951511.pdfIn PDF document text
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/pe4fbdjp2h2krm38e32m159td4/zebenegivoparolopefato.pdfIn PDF document text
    • http://allasclub.com/campannas/file/23258601785.pdfIn PDF document text
    • http://thepokewave.com/uploads/files/26734124563.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ace3c7ec19d---dupuvazisedokepoberevuba.pdfIn PDF document text
    • http://libron.pl/fckupload/assets/file/lilibekaxojasixagi.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f025a217d3---xofujor.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094ddfdf2c2a---83268235821.pdfIn PDF document text
    • https://realestateconnect.pro/wp-content/plugins/super-forms/uploads/php/files/bi7d17h1k8m7bm18oeodkg97c2/nupisigenoduno.pdfIn PDF document text
    • https://alula.com/wp-content/plugins/super-forms/uploads/php/files/4cc52021df301b36c33b534b85fddfe2/risufezotelevomuwodo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f3d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3D8 5488 bytes
SHA-256: e492eed07c3396929b2851f094461e54fbdb0331a893ebf3ea8bd773c2b2f3f5
font_01_sfnt_off00010675.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10675 11776 bytes
SHA-256: b1ac8ac184fc7a222175944e619aee9dba70b82c058f2d80704a015c1c721c48