Malicious PDF — malware analysis report

Static analysis result for SHA-256 81723fc8d7725502…

MALICIOUS

PDF

79.0 KB Created: 2021-03-25 10:08:54 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 36fc099748274cce44555bf332afb081 SHA-1: ef34dbdc8dd5d1f0247bf09ce3c615b2b1c26ab0 SHA-256: 81723fc8d7725502c8f55cbe3d315347119e2a2958ddddb2a86afc5cabcbd37c
66 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains multiple embedded URLs, with one specifically referencing an 'english grammar test'. The ML classifier strongly indicates maliciousness, and the presence of numerous external links suggests a link farm or redirection mechanism. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware delivery attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 4

  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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 https://kuzutuzo.ru/award?keyword=english+grammar+test+grade+7+pdf PDF link annotation
    • http://pugolasasiv.22web.org/auto_call_recorder_pro_app_apk.pdfIn PDF document text
    • https://cdn.sqhk.co/lofesaxudiwo/hgAigl6/radiology_technician_jobs.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4419630/normal_5feeb177a3a89.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417033/normal_5ff76da034743.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403413/normal_5fecf3d4d401f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403952/normal_6051ef0f2d4c3.pdfIn PDF document text
    • http://kebuluwe.iblogger.org/xaligopejipuluwa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4466413/normal_605af778d5c5a.pdfIn PDF document text
    • https://cdn.sqhk.co/ravawiku/hggdjcx/mesivudi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4466154/normal_6015d9a188252.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475741/normal_6049f513ec404.pdfIn PDF document text
    • http://muzojumovove.iblogger.org/vizio_sound_bar_manual_sb36512-f6.pdfIn PDF document text
    • https://cdn.sqhk.co/xasexuwosul/hc7bSgd/bts_run_ballad_mix.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://wanudoxemix.epizy.com/3915200062.pdfIn PDF document text
    • https://064d663d-f6b2-44cf-a6ad-083da5f315e5.filesusr.com/ugd/77eba6_1769350e6c614dd9bb33398383d7f60c.pdf?index=trueIn PDF document text
    • http://vewokepewaki.epizy.com/52496688967.pdfIn PDF document text
    • https://02796127-04ec-4c85-b270-c6f7310ebb18.filesusr.com/ugd/ce0e6d_a0536e84f370450f8a0a4dadf1f5e386.pdf?index=trueIn PDF document text
    • https://4ad55601-b8ab-4ae0-bc0e-e90069072326.filesusr.com/ugd/3aca14_f0985c2eb9f44bf7895bf10d86021273.pdf?index=trueIn PDF document text
    • https://7c9e9c40-2b96-4f88-8065-b5ff5e495659.filesusr.com/ugd/3bfcae_ca3e1d8d5e5345fe9f0a0f1f8944b3cb.pdf?index=trueIn PDF document text
    • https://def05634-b969-4265-beeb-1e7d695e9a44.filesusr.com/ugd/6865ce_c746bc9d09ce458e8042fd611b1e31b9.pdf?index=trueIn PDF document text
    • https://0ffdd24b-620b-4f4d-94ef-a39da1ca20bd.filesusr.com/ugd/853ce2_1cc7bba221684d7aa47819a0c1467ef2.pdf?index=trueIn PDF document text
    • https://0491f86b-060d-4f4a-be23-b0d01488777f.filesusr.com/ugd/faa7ef_793295c7e0e546e8ac1af8ba7076a489.pdf?index=trueIn PDF document text
    • https://2b4b9a66-705d-4e40-a31d-28d4db190467.filesusr.com/ugd/1dbb98_ec3c3f77ebbb4f4a8cca30ace0dcd783.pdf?index=trueIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f63b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF63B 5492 bytes
SHA-256: 6550a417373939ed42fa91786e819a5a2e64199ab14bdd94fe825f97982f18f0
font_01_sfnt_off000108ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108CA 11368 bytes
SHA-256: 719dc20881597dbe22ae922b5ba66ca88efa3ab1231b4f50339677bf61ce893b

Open this report in the interactive analyzer, or submit your own file for analysis.