Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a3f11b791609805…

MALICIOUS

PDF

75.7 KB Created: 2021-09-09 18:23:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: f5ca5b7e44568f9313affa00670a02af SHA-1: fc0c4997f4cc23b27f50936d665eb0e1a10c9887 SHA-256: 9a3f11b7916098056beff7a1fd4a29df63eceabb304428ac65c2a42ba8f48f7e
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many of which point to other PDF files hosted on potentially compromised or disposable domains, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. The presence of multiple PDF link farm heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://xn--p3t29jo1ed4o4xw.tw/upload/files/57778245846.pdf In PDF document text
    • http://www.tobywells.org/media/fckdir/file/bujositonedukugopunaxob.pdfIn PDF document text
    • http://sunnyten.net/userData/board/file/debumi.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131bbff09aad---wunesaxupenizovurug.pdfIn PDF document text
    • http://miet-boot.ch/images/uploadedimages/file/58109175413.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff42851468---muxizenitufosefobutimer.pdfIn PDF document text
    • http://okna-kurska.ru/page_edit/_samples/userfiles/files/23262247515.pdfIn PDF document text
    • https://aspit.ro/imagini_ws/58455195328.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16134698d8aa44---1984899000.pdfIn PDF document text
    • https://olamare.com/img/uploaded/file/xobepomu.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/f10f7ec62e5183676d6dbacddef2bed8/69324005692.pdfIn PDF document text
    • https://valeaflorilor.ro/img/uploads/file/bikubexojewufedawefabek.pdfIn PDF document text
    • http://daoltrading.com/userData/board/file/dodisepa.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/fadff3ce497d806e8c53421cfa406776/45662935024.pdfIn PDF document text
    • http://saaretravel.ee/images/file/4376428501.pdfIn PDF document text
    • http://yunnanyingxiang.com/ckfinder/userfiles/files/33101553474.pdfIn PDF document text
    • http://mayingiabao.com/upload/files/soterumutelalaj.pdfIn PDF document text
    • https://dispecom.com/cms_dispecom/sgi_userfiles/userfiles/files/97845212323.pdfIn PDF document text
    • http://jsqnchem.com/upload/files/27102326731.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/jugusujelezobusurazodi.pdfIn PDF document text
    • http://le-nora.com/userfiles/file/5275996048.pdfIn PDF document text
    • http://xedaphcm.com/luutru/files/93920653515.pdfIn PDF document text
    • http://gz-chengeng.com/uploadfile/files/91514306280.pdfIn PDF document text
    • http://easy-sleep24.de/shop/images/editorfiles/file/fuzifivawuzav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=scary+games+unblocked+66PDF 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_off0000c3b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3B7 11212 bytes
SHA-256: 0be05a0cd73edcb2cbbc57f669dea1a90abbeaddbb7ad828bf3a3a6c63d22407
font_01_sfnt_off0000ddc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDC5 16748 bytes
SHA-256: 30945187cc4cbde531e9c5b28032840a5945e8d0a24b01ff75c26a0cc6c8af9f
font_02_sfnt_off000108b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1