Malicious PDF — malware analysis report

Static analysis result for SHA-256 404400e81eb57e3f…

MALICIOUS

PDF

28.3 KB Created: 2018-06-11 09:59:13 -04:00 Authoring application: wkhtmltopdf 0.12.4 (via Qt 4.8.7) First seen: 2020-09-24
MD5: f9ef36fd98c7c8ebbedfd177df35b2a6 SHA-1: 71846cb9e73aeeb14d8b276279bbb876de5e779e SHA-256: 404400e81eb57e3f770cf2fd8551272be0b25b24beb226f4eba84b641ae36afc
130 Risk Score

Malware Insights

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

The PDF file was flagged by an ML classifier as malicious with a high probability. It contains embedded URLs that point to external domains, specifically 'uncpbisdegree.com' and 'riverside-resort.net', which are likely used to host or redirect to malicious content. The presence of a 'download button' heuristic further suggests a user-interaction-based lure. No scripts were extracted, limiting the analysis of specific payload delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9680

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=snap-shot-of-belize-an-anthology-of-short-fiction-belizean-writers-series.pdf In PDF document text
    • http://uncpbisdegree.com/download4.php?q=snap-shot-of-belize-an-anthology-of-short-fiction-belizean-writers-series.pdfIn PDF document text
    • http://riverside-resort.net/1/the-origin-of-satan-how-christians-demonized-jews-pagans-and-heretics.pdfIn PDF document text
    • http://riverside-resort.net/1/the-black-duck-historical-fiction-by-janet-taylor.pdfIn PDF document text
    • http://riverside-resort.net/1/the-sasha-mccandless-series-volume-2-books-4-5-5.pdfIn PDF document text
    • http://riverside-resort.net/1/the-masnavi-book-three-oxford-worlds-classics.pdfIn PDF document text
    • http://riverside-resort.net/1/the-sun-also-rises-ernest-hemingway.pdfIn PDF document text
    • http://riverside-resort.net/1/the-correspondence-of-isaac-newton-vol-1-1661-1675.pdfIn PDF document text
    • http://riverside-resort.net/1/solid-mensuration-solution-manual.pdfIn PDF document text
    • http://riverside-resort.net/1/toyota-pickup-fuse-box-diagram.pdfIn PDF document text
    • http://riverside-resort.net/1/the-last-degree.pdfIn PDF document text
    • http://riverside-resort.net/1/teksing-towards-math.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_off0000336d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x336D 10544 bytes
SHA-256: c1786ba5c5595e97719647046304bbd22ae0b70827f1edb578048bb945321f70
font_01_sfnt_off000054e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x54E4 7360 bytes
SHA-256: 8522a086e18eb320a211a53d99313a96ec280d1cc71e6a7ba75768678f2a7015

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