Malicious PDF — malware analysis report

Static analysis result for SHA-256 de87fb0c42f73b86…

MALICIOUS

PDF

28.2 KB Created: 2018-06-11 09:38:50 -04:00 Authoring application: wkhtmltopdf 0.12.4 (via Qt 4.8.7) First seen: 2020-08-25
MD5: 3c1ab74fcb1513771cd6d948f3273284 SHA-1: 8621039ebf80fd567f83e8eee1e0171d4f60844b SHA-256: de87fb0c42f73b868a1941869e7a5c573fae95afcfc6f44b68f83a8cbfff26f1
130 Risk Score

Machine Learning

  • Nyx PDF Classifier malicious score 0.9302

Heuristics 4

  • Fake 'free download' SEO-poisoning PDF critical PDF_SEO_FAKE_DOWNLOAD
    The ML classifier flagged this PDF AND it carries a visual download/call-to-action lure AND an off-domain server-side download-gateway link whose query string names a document payload. This three-signal conjunction is the fake-document / 'free PDF download' SEO-poisoning delivery pattern: the page is padded with benign decoy links to dilute classifier scores while funnelling the victim through the gateway to malware/scareware. Acting only on the conjunction keeps benign download-bearing PDFs from being misflagged.
  • PDF carries a PHP-gateway SEO-spam PDF link farm medium PDF_SEO_PHP_GATEWAY_LINK_FARM
    PDF contains four or more clickable links whose target is a `.php` gateway with a multi-word search-PHRASE document slug embedded after it (e.g. 'index.php?.../binary+options+trading+nz.pdf' or 'pdf.php/cialis-dosage-side-effects.pdf'). Legitimate PHP-served documents use a filename or numeric id, not a search-query phrase, so this is the generated SEO link-farm shape — pharma / binary-options / 'free download' spam that ranks for queries and routes users into payload/redirect chains. 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
  • 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://uncpbisdegree.com/download3.php?q=sjpo-2011-answer.pdf In PDF document text
    • http://uncpbisdegree.com/download4.php?q=sjpo-2011-answer.pdfIn PDF document text
    • https://www.physics.com.sg/PhysicsIP.htmIn PDF document text
    • http://www.sji.edu.sg/news-and-events/news-highlights/2012In PDF document text
    • http://riverside-resort.net/1/shotokan-karate-guide.pdfIn PDF document text
    • http://riverside-resort.net/1/twilight-of-the-vuvuzelas-madam-eve-collection.pdfIn PDF document text
    • http://riverside-resort.net/1/trucks-whizz-zoom-rumble.pdfIn PDF document text
    • http://riverside-resort.net/1/toshiba-satellite-l10-manual.pdfIn PDF document text
    • http://riverside-resort.net/1/turkey-dictatorship.pdfIn PDF document text
    • http://riverside-resort.net/1/social-perspectives-in-r-k-narayan-novels-1s.pdfIn PDF document text
    • http://riverside-resort.net/1/sprint-phone-connect-manual.pdfIn PDF document text
    • http://riverside-resort.net/1/uf-health-cancer-center-orlando.pdfIn PDF document text
    • http://riverside-resort.net/1/the-metal-clay-techniques-book-the-complete-guide-for-jewellery-makers.pdfIn PDF document text
    • http://riverside-resort.net/1/thumbelina-other-fairy-tales.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://go.microsoft.com/fwlink/?LinkId=521839&CLCID=0409In PDF document text
    • http://go.microsoft.com/fwlink/?LinkID=246338&CLCID=0409In PDF document text
    • https://go.microsoft.com/fwlink/?linkid=868922In PDF document text
    • http://go.microsoft.com/fwlink/?LinkID=286759&CLCID=409In PDF document text
    • http://go.microsoft.com/fwlink/?LinkID=617297In PDF document text
    • https://fedoraproject.org/wiki/Licensing/LiberationFontLicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000347e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x347E 10032 bytes
SHA-256: 31aef5bb5ac202283ac8256f9f8e01df51bb99d4a1582492283376cba60abdc5
font_01_sfnt_off00005450.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5450 7164 bytes
SHA-256: aae86d40347ab9db96004f5cb31ab68bc5a51ab678b8bd8f321ebd1053b63a75