Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4bad3eabab6d6d9…

MALICIOUS

PDF

85.2 KB Created: 2021-09-23 08:05:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e9511c3c053b1a35e4220ddefd8733a4 SHA-1: f4fcfb4517d99606149d68a27d27347c9efafe02 SHA-256: a4bad3eabab6d6d9a9c6dcdf7aa84a5334a258a46f2ec69fb66bd36189862693
134 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external PDF files, one of which is hosted on a potentially disposable domain. The presence of a 'download button' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://listapp.in/ci/userfiles/files/96516364765.pdf In PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/16136950b53781---sopetila.pdfIn PDF document text
    • http://kjphotocon.org/data/userfiles/files/pofufuso.pdfIn PDF document text
    • https://vietucmould.com/img-vietuc/files/dikek.pdfIn PDF document text
    • http://bjjiffy.com/upload/nurabixisawubux.pdfIn PDF document text
    • http://studioiulianella.it/userfiles/files/xufulom.pdfIn PDF document text
    • http://vinhomeshaiphong.net/app/webroot/img/files/bejubuw.pdfIn PDF document text
    • http://finpacecuador.com/userfiles/file/gesotogi.pdfIn PDF document text
    • http://ailizia.com/userfiles/3581436317.pdfIn PDF document text
    • http://thriftstorewebsites.com/flash/thriftstorewebsites.com/file/50975580549.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/h0ftto4d7kreqodc4t1jf3l0o7/zosufozin.pdfIn PDF document text
    • https://cam-ceeds.org/ckfinder/userfiles/files/78558433515.pdfIn PDF document text
    • http://disonde.com/filespath/files/20210913083131.pdfIn PDF document text
    • http://timavoshipsupply.it/userfiles/file/pakozatuwawokadivopevuxuv.pdfIn PDF document text
    • https://marblobath.com/app/webroot/img/files/22590153620.pdfIn PDF document text
    • http://dnepropress.net/files/file/42551587712.pdfIn PDF document text
    • http://skolky.info/foto/images/file/33239219822.pdfIn PDF document text
    • https://coopinproject.eu/ckfinder/userfiles/files/16522037220.pdfIn PDF document text
    • https://agmatbaa.com/upload/files/firagoxotenekitafo.pdfIn PDF document text
    • http://druckmaschinenservice.com/uploads/fce/files/18194705267.pdfIn PDF document text
    • http://ellenia3.eu/userfiles/files/vifatosikitanojibixule.pdfIn PDF document text
    • http://esistore.lu/userfiles/file/posuzikefelifo.pdfIn PDF document text
    • http://www.mattig-accounting.bg/fisiere/file/97598890685.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///78258222044.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=drastic+full+version+apkPDF 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_off0000df37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF37 10732 bytes
SHA-256: 2c37b1614d4b585416973c79885d6c6079ae578f88e1a87c75819995d0b292d2
font_01_sfnt_off0000f815.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF815 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011027.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11027 21496 bytes
SHA-256: 9604a699e75b0b8877c6bedd1142f1ec141db3ae4f4e188c48039368dab7f2ea