Malicious PDF — malware analysis report

Static analysis result for SHA-256 73ef38739a07bae9…

MALICIOUS

PDF

74.2 KB Created: 2021-04-06 09:39:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: f0ba8b93dfcf736641264358b368aaf2 SHA-1: c4b6ad7a62b2d41c3f2aa35ba69dcf7ae248620f SHA-256: 73ef38739a07bae9d5e841461240812a1292bb277c015da9bfc28d3107cdcad7
166 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution attempt. It contains multiple embedded URLs, with a high-priority heuristic identifying an invisible link to 'http://securityofusersdevicesonline.site/46726167634911so.pdf', suggesting a lure to a malicious domain. The document body, though heavily obfuscated, contains text related to 'algebra' and 'pdf', likely part of a social engineering pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Image-heavy PDF with invisible link to suspicious domain high PDF_SUSPICIOUS_LINK_LURE
    PDF is a small image-heavy lure with invisible link annotations that send the user to a suspicious high-risk-domain URI. This matches credential-phishing carriers where the visible document is only a prompt and the real collection flow happens on the linked website.
  • 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://midufefew.ru/award?keyword=beginning+intermediate+algebra+5th+edition+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4408992/normal_60013482195f3.pdfIn PDF document text
    • http://vizazovabula.mywebcommunity.org/golitebazog.pdfIn PDF document text
    • http://securityofusersdevicesonline.site/46726167634911so.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480383/normal_5fd86c242e305.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393790/normal_5fc861f7480d7.pdfIn PDF document text
    • http://girepodemaz.getenjoyment.net/best_text_editor_app.pdfIn PDF document text
    • http://es50off.pro/519737469698s3jg.pdfIn PDF document text
    • http://bonus332.site/graduation_sheet_cakes_for_guysoz96q.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451217/normal_6018662f5d22c.pdfIn PDF document text
    • http://pixxel.life/central_line_care_guidelinesws6ld.pdfIn PDF document text
    • http://myfoxing.online/duraginotem63ga.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448992/normal_6069a2ef34fb3.pdfIn PDF document text
    • http://christmas-gift.ru/acute_sinusitis_top_guidelinesfr1v0.pdfIn PDF document text
    • http://tojuvapemupo.mywebcommunity.org/palaxuluj.pdfIn PDF document text
    • http://mestikon.online/24332418560oqyed.pdfIn PDF document text
    • http://whitecheat.xyz/can_you_do_a_psychology_degree_onlinejwozr.pdfIn PDF document text
    • http://complerbnp.com/phase_1_reactions_biotransformationfzqqq.pdfIn PDF document text
    • http://bebetadiruj.mywebcommunity.org/buugaagta_barashada_afka_soomaaliga.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://000bb656-a8cb-4e8b-9327-0b0ec99f56fe.filesusr.com/ugd/3f812e_8e1d5a2de9694ba88b34bfdff9fa4ec0.pdf?index=trueIn PDF document text
    • https://e4dd5bf8-bd13-43e3-b37b-9624b2564f03.filesusr.com/ugd/093416_bd85b53e55f64d69b05c58ef19f3269c.pdf?index=trueIn PDF document text
    • https://f26e6bca-ce10-4524-9610-ed5ef7c8d48b.filesusr.com/ugd/ac8c68_9f38753a9add4cd9ab4abd2f0649b555.pdf?index=trueIn PDF document text
    • https://ad858f6a-7bbb-416d-9365-e04d7986ed9b.filesusr.com/ugd/3c9ac1_86f0bec8092a41f880c4adae06ff7d1b.pdf?index=trueIn PDF document text
    • https://8a5a474a-a671-4857-921d-d1df0ee72544.filesusr.com/ugd/523716_91e09da386784f9aa7f0ff96539d0dbb.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_off0000e448.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE448 5588 bytes
SHA-256: f0f07a8c167e8b5b4f20bf946bac47fe67c3d6c0dc6a1bae0656fc77c444558a
font_01_sfnt_off0000f71f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF71F 10588 bytes
SHA-256: 2e7698988516d288ceac411686c2cf7f7a50cc1776f666834da8a06e8e2b001a