Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8951b681910c754…

MALICIOUS

PDF

105.5 KB Created: 2021-09-01 05:09:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 41aad65e4e2b033f61150bbf6614631e SHA-1: 37fa5c0c47a16d17a86f387e4bab77c6a8fcbaa6 SHA-256: f8951b681910c754bbdd9e12d7a222d6b47a92ea7a266636e872423d500fe545
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://e-uchebnici.com/img/file/80969071206.pdf In PDF document text
    • http://szentimresiklos.hu/upload/file/zalixonelanuv.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/20581913984.pdfIn PDF document text
    • http://hoangnamjsc.com/upload/files/31663242932.pdfIn PDF document text
    • http://softtox.pl/new/userfiles/file/wowekaw.pdfIn PDF document text
    • https://tractorpulling-emmeloord.nl/upload/file/lenapoj.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161271aa7daac5---49187215278.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/vaxuned.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/5372c67aeb3b5cb8b05ac08357cdc7e0/47801598317.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160ae7a8f38467---84548378269.pdfIn PDF document text
    • https://www.newhorizonscrisiscenter.org/ckfinder/userfiles/files/xumapolufa.pdfIn PDF document text
    • http://idolyokocho.com/js/ckfinder/userfiles/files/kawukonubad.pdfIn PDF document text
    • http://aaykpn.com/uploads/editor/files/17656549228.pdfIn PDF document text
    • http://fmi.lu/userfiles/files/jipenitera.pdfIn PDF document text
    • http://stickerbarcode.com/file_media/file_image/file/mafawekagusuveko.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160771c3d119ea---jotubaje.pdfIn PDF document text
    • http://pillshop.ru/uimg/files/92994449717.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/bcgiokgspptr2gllful0rs3s84/23896146979.pdfIn PDF document text
    • https://yingzhaoliuart.com/upload/file/15682542257.pdfIn PDF document text
    • http://chithanhplastics.com/uploads/userfiles/file/zinazeragaxuroxitegil.pdfIn PDF document text
    • http://nontaromclinic.com/ckfinder/userfiles/files/bimexusawudarajewem.pdfIn PDF document text
    • http://shuimotongyuan.com/userfiles/file/94141726789.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=aims+and+methods+of+scoutingPDF 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_off000137a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137A5 10856 bytes
SHA-256: 131c886c2318448ab491346208fb47905f76d2e5ebea0c5998ef7d90fae4f0bb
font_01_sfnt_off00015054.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15054 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016866.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16866 18436 bytes
SHA-256: 34e3e73e99c43c24e8ab0ed549c13f9f2a8032607583ef0cc5dbe7950dad92cd