Malicious PDF — malware analysis report

Static analysis result for SHA-256 8832efeea8181f84…

MALICIOUS

PDF

87.6 KB Created: 2021-06-27 05:29:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 1813c61c7bda6bd3e19292cc722cd3e4 SHA-1: 842f334d70a79b7f70746efde77fecdf967ce7fb SHA-256: 8832efeea8181f847ca9062d385f9c2421dc02769e2d78fbd64fce02a454f90e
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains a large number of links, many of which point to compromised WordPress upload storage. The ML classifier strongly indicated maliciousness, and the link farm structure suggests an attempt to redirect users to potentially harmful sites. No scripts were extracted, but the primary function appears to be acting as a lure to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • 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.
  • 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://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af8b51d11b7---topesuw.pdf In PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4000bd5afb---1555920867.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083844042360---15866481367.pdfIn PDF document text
    • http://ceomit.com/fckupload/file/sesobugoluwux.pdfIn PDF document text
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/c43c3f789c24242b6a68955669bfdf85/7824660299.pdfIn PDF document text
    • http://phenix-security.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16094a468595ad---tonitegikirogoxera.pdfIn PDF document text
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/1d40e543aeab2ff52671e12c7c668124/7455355291.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/xuvazupi.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160aca5a5e736a---jojafevezifasovivevabixu.pdfIn PDF document text
    • https://cls-toronto.com/wp-content/plugins/super-forms/uploads/php/files/085a0772d9f67ec1c77af266a5ec97f9/mupizudutaxaravogerasutar.pdfIn PDF document text
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/47c76c18145ed7ab9a3b7c7331fc9a23/dorusitivokugurage.pdfIn PDF document text
    • http://amadpich.com/userfiles/file/79436076875.pdfIn PDF document text
    • https://condominiovillage.com/userfiles/file/dadasumi.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16074870e168b6---vaboromawazipejex.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/91c16f7a2e8a3f0867a5a0cf3eb8d851/nutobinazaveta.pdfIn PDF document text
    • http://vivaldiskibus.com/FileData/ckfinder/files/20210622_1476540E2D118BC3.pdfIn PDF document text
    • https://www.rowtheerne.com/wp-content/plugins/super-forms/uploads/php/files/344c9a52e99fa662742f30a573714dc7/72055985995.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9b942eace---41828253296.pdfIn PDF document text
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160ac66d927508---13055087487.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/5qsh7dh6vqu2io4807s952i1d3/rinubonefozegujapiso.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d710f308a3---mowed.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607f108bc3cef---69692643185.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/0j2ut46a1bfpphec4hemkkj9k9/17161130957.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/1c19a8d3ce74f98e00fd5a7f9d2234e1/72732140531.pdfIn PDF document text
    • http://mastera-mix.ru/ckfinder/userfiles/files/texanezotasesexipik.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=flipped+classroom+research+2019PDF 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_off0000f092.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF092 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000108a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108A4 17776 bytes
SHA-256: ac7b5e60e8a09c26bc021fca2ed377c5a10eaa651ce0aaed47539f5ec1530d85
font_02_sfnt_off000137bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137BC 11016 bytes
SHA-256: feaadc8af9b305e2b72e2aaf4154ec18f6676d4854ce260c2678dcfdded2c36e