Malicious PDF — malware analysis report

Static analysis result for SHA-256 e3b5fd5b9e2e120c…

MALICIOUS

PDF

72.9 KB Created: 2021-05-13 00:58:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 84a0676fca6d7d56e4829e41cbb6340e SHA-1: 6b4c91f05f4282500449c6cdbf9ff41679637219 SHA-256: e3b5fd5b9e2e120ced433f9bd14042e782e476170e74bb0f72792e71edaf3010
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to compromised WordPress sites, which in turn host other PDF files. This structure suggests a link farm designed to distribute malicious content, likely for phishing or malware. The ClamAV detection and ML classifier strongly indicate malicious intent, and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirms the suspicious nature of the linked domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/81dbe2780efdd55a1e2829f9d18912f9/tilasuwerewevubutejuj.pdf In PDF document text
    • https://minutesnap.com/wp-content/plugins/super-forms/uploads/php/files/9a895a33731aa14f20758db045b99032/82162958703.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/7b92b2b46c1e405310387da7a48e855b/8691772302.pdfIn PDF document text
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/b197f1ab30a46034d5e300ed28633be4/vuketilunewabigatax.pdfIn PDF document text
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/jlct9tvd23vtg03umhve53b0j6/21625163316.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/damafevezoduwiw.pdfIn PDF document text
    • https://munord.com/wp-content/plugins/super-forms/uploads/php/files/bb8e6de543af30b7b205b506151279e2/37036998648.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/844babd34f0d472dd00176ffe61e0a5d/34653900942.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/7075cd343f41aa0dffd00c58e140a253/61789630465.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/a0655a169096df77c08648e2861f4de2/52843584111.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1608ebfc592c98---26254088883.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080ded3a60ba---tawuxovizoroli.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608266f61a333---71002536521.pdfIn PDF document text
    • https://big-cash.de/wp-content/plugins/super-forms/uploads/php/files/uk4e31k4nj7jfcgfer5vm7hbue/92974205078.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/aa6fd7492865ca9c06acc7a4d5d5efd3/99103815553.pdfIn PDF document text
    • https://gachbinhduong.com/upload/file/wezibiduxoxotajaxulawi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=rubicon+manual+sway+bar+disconnectPDF link annotation
    • 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_off0000dfaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFAA 5428 bytes
SHA-256: ebc529c7426aff9806aac518a0b4daa6a7ebd492b36e619111a14dba0c98b51b
font_01_sfnt_off0000f21a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF21A 10644 bytes
SHA-256: 83ee353e48998e0cc81b11c1c08f0fd93a9b4e31cf7cd37f7bba16623d7d03f5