Malicious PDF — malware analysis report

Static analysis result for SHA-256 d6b081fa5d3ddc72…

MALICIOUS

PDF

84.4 KB Created: 2021-09-01 06:19:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: c08b74c039508b0c4825a1b45fef116a SHA-1: faf92dc29c73c8b2e377440fc47e88a5d9683ea1 SHA-256: d6b081fa5d3ddc72b5d3d107a94362b3a5926e704bc3de3a49610509beb33a77
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is a PDF identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs pointing to compromised websites, indicating a link farm designed to redirect users to potentially malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, suggesting the PDF is part of a network of disposable hosting for SEO-based link farming.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://synerhu.ru/uplcv?utm_term=all+up+meaning PDF link annotation
    • https://seataclightingalaska.com/wp-content/plugins/super-forms/uploads/php/files/3d9727b4c36897a462f3f630c1c01ac0/7296367025.pdfIn PDF document text
    • http://amghanoi.com/images/ckeditor/files/1486463174.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d92660635c---63530641666.pdfIn PDF document text
    • https://sentinels.ro/userfiles/file/88978724535.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1607900269d79a---5720536138.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607633ebb3486---burome.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/0901679d7e8dd42be9534cdccae2d123/fufab.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160baa0aa6d0fa---kuwedux.pdfIn PDF document text
    • http://kleinschaden-expert.de/userfiles/file/nomexoforasukog.pdfIn PDF document text
    • http://ferramentabelleggia.it/public/file/58157134859.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e4d49f95d71---benuja.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/gk3ve28n8h85s4tds9stqa1uqq/6969180577.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b27c0bae050---58612666134.pdfIn PDF document text
    • http://challendor.com/fckeditor/upload/file/87475604462.pdfIn PDF document text
    • http://aurora-c.jp/files/files/tixut.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609d16fc642e1---90506741803.pdfIn PDF document text
    • http://project-lovcen.me/userfiles/file/29496629690.pdfIn PDF document text
    • https://contabil-fiscal.ro/mm/file/1030145782.pdfIn PDF document text
    • https://12shio2.com/contents//files/26532680069.pdfIn PDF document text
    • http://cnhhgj.com/upfiles/userfiles/file/18917717233.pdfIn PDF document text
    • http://geomanteia.com/userfiles/files/22550958439.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_off0000ea0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA0D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001021f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1021F 17112 bytes
SHA-256: 299062b55ff9ec48d1f95798973371f997a05b5fe04152d51fa9ccd045ab2e03
font_02_sfnt_off00012e31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E31 10192 bytes
SHA-256: f45c4bfc891882b02f3f05d2fcc511cada1be907c19ba5898bbaf4c71e0d460f