Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4999b1213706b69…

MALICIOUS

PDF

77.8 KB Created: 2021-04-25 05:13:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 6fd9f4ce46c5a1fc4252455f90f33c91 SHA-1: bc6c3f653e974029b2b6f89ac2b93541565c392a SHA-256: b4999b1213706b692d5c72c7d179a36eda8f9c47ff0a50b387e02fb343539dcd
186 Risk Score

Malware Insights

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

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing campaign. The document body is heavily obfuscated and contains metadata indicating it was generated by wkhtmltopdf, a tool often used to create PDFs from web content, which aligns with the link farm heuristic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://jacksth.ru/strik?utm_term=is+steelhead+and+rainbow+trout+the+same PDF link annotation
    • https://mivetemadika.weebly.com/uploads/1/3/4/4/134471856/5377918.pdfIn PDF document text
    • https://nukubutoti.weebly.com/uploads/1/3/2/3/132302768/wefata.pdfIn PDF document text
    • http://vugekowuzujed.scienceontheweb.net/brahmi_rediscovering_the_lost_script.pdfIn PDF document text
    • https://fenonurel.weebly.com/uploads/1/3/1/1/131164034/jopenatupitopovawuw.pdfIn PDF document text
    • https://mipirizu.weebly.com/uploads/1/3/2/6/132682564/3424226.pdfIn PDF document text
    • https://nomikevokatipo.weebly.com/uploads/1/3/1/8/131859895/7317384.pdfIn PDF document text
    • https://pimidunobesuxig.weebly.com/uploads/1/3/0/9/130970022/d9bc21.pdfIn PDF document text
    • https://pizakatunif.weebly.com/uploads/1/3/1/8/131856177/falabelizupadix_jugitosefatefa_zilutidib_xajuletoramij.pdfIn PDF document text
    • http://tifusavegapawuf.mygamesonline.org/deathwatch_codex_8th_vk.pdfIn PDF document text
    • https://mirulunus.weebly.com/uploads/1/3/1/1/131164386/88677.pdfIn PDF document text
    • http://serururepus.scienceontheweb.net/fogigugakujepuwebopoj.pdfIn PDF document text
    • http://fuxutigox.mypressonline.com/sujij.pdfIn PDF document text
    • http://povulofi.mywebcommunity.org/all_formula_in_excel.pdfIn PDF document text
    • https://wasitenatibasi.weebly.com/uploads/1/3/4/8/134890771/salulosikazinuv-wuwifomomak.pdfIn PDF document text
    • https://zijolafazul.weebly.com/uploads/1/3/0/8/130873795/8eab4b974bfef0.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://nezugetojuf.myartsonline.com/adiabatic_saturation_temperature.pdfIn PDF document text
    • http://lafagelupuf.myartsonline.com/76002109082.pdfIn PDF document text
    • http://xuvekixofeku.onlinewebshop.net/uscg_aeromedical_manual.pdfIn PDF document text
    • http://fuluxewamotate.atwebpages.com/25841749020.pdfIn PDF document text
    • https://dbba0f06-1911-40f0-8c80-a2638c7f81cc.filesusr.com/ugd/b13fd1_9606b854297a41bc8e3029592eaa227f.pdf?index=trueIn PDF document text
    • https://9ef77391-fdd1-48d8-ba15-364b07375333.filesusr.com/ugd/ebefdf_209570a0908543dc9aa772147fe52a92.pdf?index=trueIn PDF document text
    • http://dilutibu.onlinewebshop.net/rowomojij.pdfIn PDF document text
    • http://wenibeliso.atwebpages.com/teste_de_antiglobulina_humana.pdfIn PDF document text
    • https://5e04165b-6ab1-49a6-9937-45006fc2fbeb.filesusr.com/ugd/d19879_48bd79b8ee46433693965f780fb49ee6.pdf?index=trueIn PDF document text
    • https://cf336f9a-6a79-4542-9269-5b62d6eb69dd.filesusr.com/ugd/1daf83_5c464d8022d9485ca5bc92df73905d18.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_off0000f276.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF276 5232 bytes
SHA-256: a43e2fecdf9d662a4910106246ab8aea27bcf376d4b0936a762d2519f989afd3
font_01_sfnt_off00010422.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10422 10376 bytes
SHA-256: 32c0d5a5b4ddee221612e6a17c1af5d4dae25fe8b4720cb923601ba202e5a25e