Malicious PDF — malware analysis report

Static analysis result for SHA-256 5d99dc135fe824d2…

MALICIOUS

PDF

93.0 KB Created: 2021-09-05 12:42:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 024932da56dd65eef4b9bdc001b5d5e3 SHA-1: 149e81f4e2ed614b3ed2c09aabd7079c8bdcde3e SHA-256: 5d99dc135fe824d2bba5ef5923391e03e03ddd3eb805c33ff16e2fb6e27be259
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm used to redirect users. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates these links are likely part of a scheme to improve search engine ranking for malicious content or to distribute malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://cavalier-hundezucht.ch/userfiles/file/32950929726.pdf In PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/h9i1ebk87jig88h85cis8qu113/mibomavakebivefegidum.pdfIn PDF document text
    • http://sromedical.com/file_media/file_image/file/dabowokab.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/242fac8ba0ae8e11435c2b9eb434b1e1/kawarudujamopixoli.pdfIn PDF document text
    • https://foodphotoshop.com/userfiles/files/76426094902.pdfIn PDF document text
    • http://terapeutickemasaze.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609467ad5e0b5---xobarilibotutupojogujufu.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074c6d2c94e9---27600338462.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/69247945315.pdfIn PDF document text
    • http://www.vljainandco.com/userfiles/files/gomofivom.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5mc8dlh4tnv7plcm1cb9nv1ed6/94571852774.pdfIn PDF document text
    • http://meubelenindex.nl/images/uploads/mujanuzuwaxelopep.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609bdc14b42bf---botaj.pdfIn PDF document text
    • https://aep-tc.com/cache/fck_files/file/51069071894.pdfIn PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/98409b8241ed0dacd8a0d4f6bb805be2/77533974356.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/5978c7bde5b8f6955c7284d5153b3abe/bobesevegifulexefate.pdfIn PDF document text
    • http://superbarter.sk/media/file/semivigovovosidex.pdfIn PDF document text
    • http://hillsdale66ersreunion.com/clients/c/c6/c679c52642bc64dd8629b98fb95ccc77/File/xogejekug.pdfIn PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/87187719379.pdfIn PDF document text
    • http://www.portaldasfreguesias.com/portugal/vianadocastelo/vianadocastelo/geraz_do_lima_sta_maria/ckeditor/ckfinder/file/26702022646.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160efdae08236b---61233249054.pdfIn PDF document text
    • http://koreanhotpot.com/uploads/files/31324161991.pdfIn PDF document text
    • https://ymvii.com/admin/upload/files/11473673389.pdfIn PDF document text
    • http://shbaicun.com/userfiles/file/2021073113570973499.pdfIn PDF document text
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607e9508d4bf7---35549207387.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=drunk+tank+pink+free+pdfPDF 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://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_off00010789.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10789 10352 bytes
SHA-256: ca06bcdc62bef9d9e31b90d14461a77b1d32a8eaf5c47ac1e579f0f9461c540c
font_01_sfnt_off00011f09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F09 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001371b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1371B 18148 bytes
SHA-256: ea021ff9f5a19e7aacbd2ab7194cd1f1bb0a8db7c84e5229b064376174e8522e