Malicious PDF — malware analysis report

Static analysis result for SHA-256 c92b35a9f2dd35e4…

MALICIOUS

PDF

81.3 KB Created: 2021-09-09 00:54:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0924ae909a813f6116ec0a134b5fc6db SHA-1: 4348d676c7367591ce1fc133c38a1d4445f2826f SHA-256: c92b35a9f2dd35e49595dc7b71fb69b4d86855a17beea6d26590bbb4728eef21
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded links, many pointing to unknown domains, and one heuristic specifically flags it as a link farm on disposable hosting. The `wkhtmltopdf` authoring application suggests it may have been generated programmatically to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://mottaing.eu/userfiles/files/pimatebupifetaw.pdf In PDF document text
    • http://zhongguohuachun.com/d/files/ligivamobise.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137e0da0bb6b---7143836428.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/furato.pdfIn PDF document text
    • http://myhomeinparis.com/userfiles/files/kefigubufukusapexifutej.pdfIn PDF document text
    • https://menlopark.com/wysiwygfiles/file/jixomewolizuzef.pdfIn PDF document text
    • https://a-guskov.ru/uploads/files/74584583647.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/21329354598.pdfIn PDF document text
    • https://gencshow.com/upload/ckfinder/files/nexasumuzejanu.pdfIn PDF document text
    • http://facyt.com.ar/ckfinder/userfiles/files/jawudowusiwo.pdfIn PDF document text
    • http://podarox.ru/public/files/gofuwob.pdfIn PDF document text
    • https://digireg.se/upload/vigidezuz.pdfIn PDF document text
    • http://vxclouds.com/userfiles/file/16214540829.pdfIn PDF document text
    • http://bobhendrix-law.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gokazoxabikulidiwepu.pdfIn PDF document text
    • http://phongkhamthienhoa.org/images/files/94814401181.pdfIn PDF document text
    • http://ebslang.net/_UploadFile/Images/file/wefeguf.pdfIn PDF document text
    • https://sensiblemachines.com/ckfinder/core/connector/php/files/51811471161.pdfIn PDF document text
    • http://kxqcgs.com/filespath/files/20210903084513.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613927ddbdd7f---pejimikokapar.pdfIn PDF document text
    • http://gongotour.com/FileData/ckfinder/files/20210902_023FC591B0272F16.pdfIn PDF document text
    • http://hizirferforje.com/admin/fckeditor/editor/images/file/42836056902.pdfIn PDF document text
    • http://datong-travel.tw/upload/ckeditor/files/20210902151003.pdfIn PDF document text
    • https://driftwoodcc.com/userfiles/files/fedibizedewa.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/gamerikozuwekini.pdfIn PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.net/ckfinder/userfiles/files/jupesemugakug.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=synchronise+google+contacts+with+androidPDF 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_off0000d73e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD73E 10924 bytes
SHA-256: 3fcc79961a46626b99fe4d4d78bd0a3b6557e02b58b4bb7bddabb5b021bc9c34
font_01_sfnt_off0000f057.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF057 18044 bytes
SHA-256: 1b60d45dd625c9d6ace026a7c9c1612e6d5692ca961c83ae257fbc56b27e034e
font_02_sfnt_off00011eb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EB1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1