Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4fafb7e05d9b740…

MALICIOUS

PDF

71.0 KB Created: 2021-09-27 03:21:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c677597944ade19262061f98dc0a3bb0 SHA-1: 89be0a44c2f82c06ea91d8274d7d5056fc6ee140 SHA-256: a4fafb7e05d9b7407e2f259ac6d6e1e792f6439fc2d56213fa3699da112ecfce
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The document contains numerous embedded URLs, many of which point to PDF files hosted on various domains, suggesting a link farm or distribution network. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a potential SEO manipulation or content distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://rydelko.pl/userfiles/file/zowugemavotivadali.pdf In PDF document text
    • http://nanoservice.sk/upload/file/73148905992.pdfIn PDF document text
    • http://myphamso1.net/uploads/files/boxurama.pdfIn PDF document text
    • http://aristosaigonhotel.vn/uploads/files/76843464388.pdfIn PDF document text
    • http://johnlillylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/juzukizitapaz.pdfIn PDF document text
    • https://familienbilstrup.dk/userfiles/file/68185029464.pdfIn PDF document text
    • https://namratalakhotia.com/userfiles/files/lupabupopozugofipakuluti.pdfIn PDF document text
    • https://tcremich.lu/files/files/10636101295.pdfIn PDF document text
    • http://renknh.com/ckupload/files/37633631146.pdfIn PDF document text
    • https://birutelorasin.com/contents/files/bifasegexufotimamilokozu.pdfIn PDF document text
    • http://boletin.alicantehosteleria.com/lib/ckfinder/userfiles/files/95459223983.pdfIn PDF document text
    • http://flapboxes.com/userfiles/files/nodijizodidufi.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/2ff57141018bd3e01b62093b321473f1/texiwuwonaxurepinivomu.pdfIn PDF document text
    • https://motodubai.com/uploaded_images/files/wosepowex.pdfIn PDF document text
    • https://sitycare.com/FCK-UserFiles/files/mobitasunojofufusizinig.pdfIn PDF document text
    • https://contemporaryteas.in/admin/uploads/file/41783484028.pdfIn PDF document text
    • https://jkmart.net/FCKFiles/File/kumupimasojomelugupabe.pdfIn PDF document text
    • http://grafiport.com/userfiles/file/bezuvejane.pdfIn PDF document text
    • https://jairdefreitas.com/ckfinder/userfiles/files/jeroluxowifitujulepozezi.pdfIn PDF document text
    • http://saaretravel.ee/images/file/44144158769.pdfIn PDF document text
    • https://svingenieria.cl/userfiles/file/51653844647.pdfIn PDF document text
    • http://dansensvenner.dk/imagesfile///34731232158.pdfIn PDF document text
    • http://akatumusics-ang.communication-pro.fr/public/1283/contenu/file/buxirakititorozub.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=instagram+free+followers+increasePDF 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_off0000b460.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB460 10716 bytes
SHA-256: a27b00a0beaab4fb5e791f928addd45e48fcbba983852765c6220e0ae935d912
font_01_sfnt_off0000cd05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD05 16292 bytes
SHA-256: c8b265ae166fe5b3a75947781b8f37b5da42659e205d7c5b7c3dd3ba74f9a7f5
font_02_sfnt_off0000f5f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1