Malicious PDF — malware analysis report

Static analysis result for SHA-256 d762ea5eb5d3fb17…

MALICIOUS

PDF

47.4 KB Created: 2018-06-11 09:01:43 -04:00 Authoring application: wkhtmltopdf 0.12.4 (via Qt 4.8.7) First seen: 2020-09-24
MD5: a186d15aa588051e687e038d9ad920f5 SHA-1: 4f2230db7bdaff08cfd0d16745ca577b6f2d4467 SHA-256: d762ea5eb5d3fb173158d22784af14d7283f9d842f2aed175357aef5a46a7cdb
130 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded URLs that mimic a legitimate educational resource, specifically a 'sunshine math 6th grade answer key'. The presence of a PDF_URI heuristic firing and multiple unknown reputation URLs associated with downloading this 'answer key' suggests a phishing or malware distribution attempt. The ML classifier also flagged this PDF as malicious. The document body, though heavily obfuscated, contains references to these download URLs, reinforcing the lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9273

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=sunshine-math-6th-grade-answer-key.pdf In PDF document text
    • http://uncpbisdegree.com/download4.php?q=sunshine-math-6th-grade-answer-key.pdfIn PDF document text
    • http://www.lcps.org/page/57891In PDF document text
    • http://www.lcps.org/Page/57896In PDF document text
    • http://www.lcps.org/sanderscornerIn PDF document text
    • http://fogcom.de/sunshine/math/sunshine_math_6th_grade_answer_key.pdfIn PDF document text
    • http://cabaretveracruz.com/online/sunshine-math-6th-grade-answer-key.pdfIn PDF document text
    • http://libtec.de/sunshine/math/sunshine_math_6th_grade_answer_key.pdfIn PDF document text
    • http://canrei.de/sunshine/math/sunshine_math_grade_6_answer_key.pdfIn PDF document text
    • http://riverside-resort.net/1/usermanual-for-samsung-wave-y-s5380.pdfIn PDF document text
    • http://uncpbisdegree.com/1/shirley-susan-scarf-merrell.pdfIn PDF document text
    • http://riverside-resort.net/1/writing-a-response-paper-example.pdfIn PDF document text
    • http://uncpbisdegree.com/1/skidoo-formula-repair-manual.pdfIn PDF document text
    • http://uncpbisdegree.com/1/the-advanced-pilot-s-flight-manual.pdfIn PDF document text
    • http://uncpbisdegree.com/1/test-form-3b-answers.pdfIn PDF document text
    • http://riverside-resort.net/1/usa-eoc-history-test-prep-answer-key.pdfIn PDF document text
    • http://riverside-resort.net/1/weather-maps-gizmo-answer-key.pdfIn PDF document text
    • http://uncpbisdegree.com/1/study-in-australia-scholarship-for-international-students.pdfIn PDF document text
    • http://uncpbisdegree.com/1/stentless-bioprostheses.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://sunshinemathblog.blogspot.com/2013/03/6th-grade-sunshine-math.htmlIn PDF document text
    • http://www.commonsensemedia.org/website-reviews/ixlIn PDF document text
    • http://go.microsoft.com/fwlink/?LinkID=617350In 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://769693.r.bat.bing.com/?ld=d3JOAYCUrBW7r-U-9bBikvXjVUCUzs1paEHlhIzg63pCflFpQN5M-XJt-ghccN8PrOMgBdGOvo91UyzKZdrnQSYjfqnGXamOFmip0VPR9BQQ5gz_JGK6iNCoCzmzVQlCZAFFi94qSLerZlXvVb4P9sYOy2QetVefWDi0hDBNHWB_8Ogr3x&u=https%3a%2f%2fwww.ixl.com%2f%3fpartner%3dbing%26adGroup%3d6th%2bgrade%2bmath%26campaign%3d1426%26msclkid%3d%7bmsclkid%7d%26utm_source%3dbing%26utm_medium%3dcpc%26utm_campaign%3dSearch%2520-%2520Grade%2520Levels%2520-%2520Mod%2520Broad%2520-%2520US%26utm_term%3d%252Bmath%2520%252B6th%2520%252Bgrader%26utm_content%3d6th%2520grade%2520mathIn 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_off00006b6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6B6B 14604 bytes
SHA-256: 2b4b2105811e01f5f7d1518e06dd5329a6274163b1722270417e5f24de3470b0
font_01_sfnt_off000097dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x97DD 9108 bytes
SHA-256: 92bc2ec95779e99b1b4892c7c1fcab301ff8b30127a45dc705a8ed7cc877d277