Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c3629ea5fc22b35…

MALICIOUS

PDF

82.2 KB Created: 2021-09-18 12:54:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ade5e8315d80cabd02cf4bf150d8924c SHA-1: 7437fbe42fcc2180b9786eb7c7baddd2ca9548fa SHA-256: 5c3629ea5fc22b35c41a305ec6e6b0d0a9080ea07847cae2f73764040d57cb25
174 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and multiple external URIs, indicating it is designed to interact with external resources. The 'Browser extension / update installation lure' heuristic strongly suggests a social engineering attempt to trick the user into downloading and executing further malicious content. The ML classifier and ClamAV detection further support its malicious nature, likely as a downloader or phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://zenit-npk.ru/files/file/gibujenarodanuxibufowemix.pdf In PDF document text
    • http://123podkrovie.sk/editor_uploads/files/rulodutosa.pdfIn PDF document text
    • http://extrastyle.ee/ckfinder/userfiles/files/rinibiwidi.pdfIn PDF document text
    • http://dansecyr.ca/pdf/file/wakeburetusevajofivasipum.pdfIn PDF document text
    • https://biothiennam.com/media/ftp/file/kolebapisupegun.pdfIn PDF document text
    • http://vitalchurchesinstitute.com/files/file/35703859580.pdfIn PDF document text
    • http://inventory-acepipe.com/images/uploads/files/dalozoduzadosobo.pdfIn PDF document text
    • https://ausztriasi.spawellness.hu/upload/hirlevel/files/628536584.pdfIn PDF document text
    • https://kiptep.ru/file/97415079099.pdfIn PDF document text
    • http://h-n-s.net/userfiles/file/bikazeb.pdfIn PDF document text
    • http://oecschool.com/userfiles/file/sodusuxare.pdfIn PDF document text
    • https://alicantea.centralcms.cloud/galeria/files/59913311715.pdfIn PDF document text
    • https://flour.co.uk/ckfinder/userfiles/files/madovekexemav.pdfIn PDF document text
    • https://anpheatingandac.com/nbloom/fckuploads/file/26528807334.pdfIn PDF document text
    • http://hokkaido-love87.com/app/webroot/js/ckfinder/userfiles/files/mamifudijuzokoga.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/68872890969.pdfIn PDF document text
    • http://lukinserv.hu/file/fuvozegab.pdfIn PDF document text
    • http://baldonimarcostudio.eu/userfiles/files/14565735659.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130cf6cb1c6c---rogodubolebadimaruresas.pdfIn PDF document text
    • http://carneslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/93655708659.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/b7fd14c303c6d9a584471e1dd62749ee/57026117017.pdfIn PDF document text
    • https://essuances.com/ckfinder/userfiles/files/72193740121.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=chrome+download+pending+problemPDF 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_off0000dc0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC0C 10828 bytes
SHA-256: 7697c94c4c3aa621e39d879431f034f3113d81e6bc757cd1f9431f5b31e05084
font_01_sfnt_off0000f45f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF45F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C71 17936 bytes
SHA-256: 879fe30573b6bc684f8befb86d8d1593bdc84eae180a7e3ba1b917fdf839463b