Malicious PDF — malware analysis report

Static analysis result for SHA-256 a87bcb83443ebc6f…

MALICIOUS

PDF

79.5 KB Created: 2021-06-11 13:48:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 92c95b92e0a0b5b1154e67fad3c564dd SHA-1: 4556b2e45d71c0ed2605457f9a005fe1f96e873f SHA-256: a87bcb83443ebc6f221c355b347313ff97366de98066dc1853480ee8bcc3543e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised websites and disposable hosting domains. The embedded URLs and the nature of the link farm suggest the primary goal is to redirect users to phishing sites or download further malware.

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://archism.ru/uplcv?utm_term=x+force+civil+3d+2019 PDF link annotation
    • https://muzeumkonstancina.pl/attachments/file/vadutu.pdfIn PDF document text
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/2172b9763ddced141b8eae18b43a0f35/39649843806.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609e0df37214c---fumarabul.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a78761eb69a---30688972557.pdfIn PDF document text
    • http://brno-skoleniridicu.cz/ckfinder/userfiles/files/wuluvibixasekuxozizu.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/41dc0c7d36f51aeb71cce295620d594b/23400375292.pdfIn PDF document text
    • https://refour.eu/wp-content/plugins/super-forms/uploads/php/files/ffe542c6c9f844f76e0a3fd2df71966f/23508219229.pdfIn PDF document text
    • http://maidichike.com/upload/files/20500862369.pdfIn PDF document text
    • https://www.sadcmedia.com/wp-content/plugins/super-forms/uploads/php/files/fnhnju7tpevobrefpvvvvt5782/48968508602.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/03scv7h0k7taaqofor7hbi38rn/13799591068.pdfIn PDF document text
    • http://csc010.com/userfiles/file/20210611075109_wa60vn.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ac2366e7fec---48451509379.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b127f013a64---wurugofesimelodegejemaso.pdfIn PDF document text
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/ed1d5831c347b0a8fceeec03b9842a47/dugadolorenewaliponavigo.pdfIn PDF document text
    • http://svsteinfurth.de/radsportfiles/file/mazopuzoxulud.pdfIn PDF document text
    • http://hocikto.info/userfiles/file/2078557427.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
    • 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_off0000e21a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE21A 5308 bytes
SHA-256: 662672633c41cff7afae6cb67207b83bbc198a7ec4d7cc8dd5bd0fb9270e194f
font_01_sfnt_off0000f44a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF44A 12328 bytes
SHA-256: afe0be1e3f0c392593540ecd2addf1ce5de53c01dbf49492a4585060b10976e0
font_02_sfnt_off00011c00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C00 16188 bytes
SHA-256: ef03f2fd61fb0e93cd6efb658d2abc0ef65c0fc4aca9cb2fba1c13d00ce4a728