Malicious PDF — malware analysis report

Static analysis result for SHA-256 81c5f2e3af661cfd…

MALICIOUS

PDF

31.8 KB Created: 2018-06-11 09:17:46 -04:00 Authoring application: wkhtmltopdf 0.12.4 (via Qt 4.8.7) First seen: 2020-09-04
MD5: 266fa8807a71e734b7fb1c30a889ea3d SHA-1: 4e0785ff43cb275c4bd96c4b8a75d92bdf882aa5 SHA-256: 81c5f2e3af661cfd24f9f8f3dc32beb02fa5fe68f2aeb9170bf359bba333e65c
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file is identified as malicious by an ML classifier and exhibits characteristics of SEO poisoning, specifically a fake download lure. It contains links to external URLs, one of which, http://uncpbisdegree.com/download3.php?q=the-role-of-mathematics-in-physical-sciences-interdisciplinary-and-philosophical-aspects.pdf, is flagged as a gateway for a fake download. The document's content and structure suggest an attempt to trick users into downloading a potentially harmful file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9326

Heuristics 5

  • 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 link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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=the-role-of-mathematics-in-physical-sciences-interdisciplinary-and-philosophical-aspects.pdf PDF link annotation
    • http://uncpbisdegree.com/download4.php?q=the-role-of-mathematics-in-physical-sciences-interdisciplinary-and-philosophical-aspects.pdfIn PDF document text
    • http://mathrising.com/In PDF document text
    • http://www.acpaweb.org/employment/In PDF document text
    • https://www.roosevelt.edu/academics/programsIn PDF document text
    • http://uncpbisdegree.com/1/statics-and-dynamics-hibbeler-13th-edition-solutions-manual.pdfIn PDF document text
    • http://uncpbisdegree.com/1/sony-rm-mzr55-universal-remotes-owners-manual.pdfIn PDF document text
    • http://uncpbisdegree.com/1/sources-and-fates-of-aquatic-pollutants.pdfIn PDF document text
    • http://uncpbisdegree.com/1/she-wolves-the-women-who-ruled-england-before-elizabeth.pdfIn PDF document text
    • http://uncpbisdegree.com/1/supersonic-sc-1029mp3-mp3-players-owners-manual.pdfIn PDF document text
    • http://riverside-resort.net/1/valve-timing-diagram-for-a-maruti-diesel-engine.pdfIn PDF document text
    • http://uncpbisdegree.com/1/super-photon.pdfIn PDF document text
    • http://riverside-resort.net/1/uverse-manual.pdfIn PDF document text
    • http://uncpbisdegree.com/1/the-classical-language-of-architecture-world-of-art.pdfIn PDF document text
    • http://riverside-resort.net/1/worksheet-unit-circle.pdfIn PDF document text
    • https://lt.org/In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://en.wikipedia.org/wiki/Physical_scienceIn PDF document text
    • http://www.cwu.edu/In PDF document text
    • http://www.mdpi.com/2504-3900/1/9In PDF document text
    • http://catalog.pvamu.edu/academicprogramsanddegreeplans/marvindandjunesamuelbrailsfordcollegeofartsandsciences/socialworkbehavioralpoliticalsciences/In PDF document text
    • http://catalog.iastate.edu/collegeofagricultureandlifesciences/biology/In PDF document text
    • http://www.iep.utm.edu/foucault/In 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_off000041cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x41CB 10696 bytes
SHA-256: e8cd50885b367293ed215f5cce8638c03032e1a7c337018a6e59f78085223400
font_01_sfnt_off0000638f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x638F 6684 bytes
SHA-256: 1ca35f6e60acf2de72e90a4be8875ff85b6783298bb6d1dda5ce731f9ff6a645