Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1a5aac8f21f8a8f…

MALICIOUS

PDF

28.3 KB Created: 2018-06-11 08:47:10 -04:00 Authoring application: wkhtmltopdf 0.12.4 (via Qt 4.8.7) First seen: 2020-09-24
MD5: 8dda8374851dc2f122a311a88a5c3ff5 SHA-1: d70a68a15c81d6f6f9501f2300952400c677663b SHA-256: a1a5aac8f21f8a8f3e5843de31c5b203afbba5e4dbb3c23786726478909412af
130 Risk Score

Malware Insights

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

This PDF is classified as malicious due to heuristics indicating it is a fake download lure designed for SEO poisoning. It contains embedded URLs pointing to potentially malicious download sites, such as http://uncpbisdegree.com/download3.php?q=suzuki-g10a-engine-specif.pdf. The document body, though partially corrupted, also contains references to these URLs, reinforcing the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9135

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=suzuki-g10a-engine-specif.pdf In PDF document text
    • http://uncpbisdegree.com/download4.php?q=suzuki-g10a-engine-specif.pdfIn PDF document text
    • http://riverside-resort.net/1/the-aunts-come-marching.pdfIn PDF document text
    • http://riverside-resort.net/1/servisno-uputstvo-za-automobile.pdfIn PDF document text
    • http://riverside-resort.net/1/the-wailing-wind-navajo-mysteries-15-tony-hillerman.pdfIn PDF document text
    • http://riverside-resort.net/1/the-roiling-darkness.pdfIn PDF document text
    • http://riverside-resort.net/1/teaching-transparency-chemical-equilibrium-answer-key.pdfIn PDF document text
    • http://riverside-resort.net/1/the-moth-kindle-edition-adam-gopnik.pdfIn PDF document text
    • http://riverside-resort.net/1/the-mother-in-law.pdfIn PDF document text
    • http://riverside-resort.net/1/the-andy-warhol-diaries.pdfIn PDF document text
    • http://riverside-resort.net/1/the-works-escorts-a-foulis-motoring-book.pdfIn PDF document text
    • http://riverside-resort.net/1/stock-vector---mothers-day-greeting-card-design-elements-and-backrounds-2.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_off000033af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x33AF 10248 bytes
SHA-256: a9fddf979b875f724860a56f0fe19c291bcaf2b7f8edf247f1b9fdbb021a1cb8
font_01_sfnt_off00005424.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5424 7456 bytes
SHA-256: b4b2d73c6ecfd256ce83cbb3264ebf00cfd76bbd0cb34440f2f2898c15bb1e98