Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1d86ff9f5f6aa29…

MALICIOUS

PDF

71.3 KB Created: 2021-10-01 01:18:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 95e80a21d1aa6c662a220854a7fcfa33 SHA-1: 794546b409ba3a39beaf7b99a990eaa773ece445 SHA-256: d1d86ff9f5f6aa29c34e16832771e986491a67ebb5456d7bca1fab4ee9742461
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF is designed to link to many disposable hosts. No scripts were extracted, but the presence of external URIs and the link farm heuristic strongly suggest the PDF's purpose is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://xaydungdonggia.com/app/webroot/files/images/pages/files/68789574454.pdf In PDF document text
    • http://julianina.dk/upload/file/22187655880.pdfIn PDF document text
    • http://aodaibooking.com/FileData/ckfinder/files/20210905_174BC2FB0C93875A.pdfIn PDF document text
    • http://swhos.com/upload/files/37041029665.pdfIn PDF document text
    • http://kmbb.at/userfiles/file/97764766834.pdfIn PDF document text
    • https://wilocom.ro/ckfinder/userfiles/files/vowokejef.pdfIn PDF document text
    • https://delphin-restaurant.com/ckfinder/upload/files/86380569776.pdfIn PDF document text
    • https://vgk.tw/upfile/files/2021/09/30/mekiranovefuz.pdfIn PDF document text
    • http://eunlocker.com/Images/Editor/file/vaborikur.pdfIn PDF document text
    • https://suruburi.net/mm/file/bixazofigivena.pdfIn PDF document text
    • http://seibyou-koujien.com/files/files/sibisedaboruzin.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613274981498d---10848524412.pdfIn PDF document text
    • http://mutamobilya.com/images_upload/files/bolejejizetobod.pdfIn PDF document text
    • http://klick-tipp.at/ckfinder/userfiles/publics/files/zumubovafonaduwejixam.pdfIn PDF document text
    • https://hippodrome-compiegne.fr/www/uploads/file/81625350013.pdfIn PDF document text
    • http://labonscafe.com/userfiles/sutusuwubijojikopojujopo.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1613b8e2ba3ef6---69364771516.pdfIn PDF document text
    • https://healthlantern.com/ckeditor/ckfinder/userfiles/files/xosoriwilidofejad.pdfIn PDF document text
    • http://aquatherm-graz.at/files/79588652176.pdfIn PDF document text
    • https://geniodelweb.com/file/fivevavupolotigajejowafa.pdfIn PDF document text
    • http://boekenwinkelindex.nl/images/uploads/1440204133.pdfIn PDF document text
    • http://wxmx.cn/upload/ckimg/files/202109172003345496.pdfIn PDF document text
    • http://client.diffuse.info/files/98981853454.pdfIn PDF document text
    • https://ewastexperts.com/userfiles/files/47654631087.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=windows+settings+middle+tickPDF 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_off0000b1cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1CB 17452 bytes
SHA-256: a2c44879d95684136f5bc6173398279ba3748223b45c1cd549ee2d0d2c9b9590
font_01_sfnt_off0000de25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE25 10624 bytes
SHA-256: 6ede86d65f49a320a016ce78b3455af4d68dbe5cc996dbf17205ad60db60e286
font_02_sfnt_off0000f644.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF644 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1