Malicious PDF — malware analysis report

Static analysis result for SHA-256 31c0a353fb5d4f0c…

MALICIOUS

PDF

76.5 KB Created: 2021-03-23 22:53:30 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 851e7e45915f974e4bb3fe3550174c65 SHA-1: 23ee5966e67c1e8524f4b7dcbd0eb8c243561ab9 SHA-256: 31c0a353fb5d4f0c7a79056168da2f8481ff1a015c72a7e44d0e0edf815178e6
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards the exploitation of PDF vulnerabilities or social engineering to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://leonvi.ru/award?keyword=calibre+guide+pdf PDF link annotation
    • https://fizubuvi.weebly.com/uploads/1/3/5/3/135301632/sewubufezetaxuvexi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403259/normal_6051c4ba88731.pdfIn PDF document text
    • http://wgathering.org/the_art_of_unit_testing_deutsche_ausgabeoxx3e.pdfIn PDF document text
    • https://pidofuvu.weebly.com/uploads/1/3/0/7/130739764/2436418.pdfIn PDF document text
    • https://wolofineso.weebly.com/uploads/1/3/4/5/134598063/demomurikulipagosob.pdfIn PDF document text
    • http://pedron.fun/2003_kawasaki_mule_550_manualbkhru.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4470040/normal_5ff84882a1391.pdfIn PDF document text
    • http://zoxodur.sportsontheweb.net/46522509569.pdfIn PDF document text
    • http://xitnet.fun/arp_4754_free7yahv.pdfIn PDF document text
    • https://tapuwapefozex.weebly.com/uploads/1/3/4/3/134350869/zaxiwidafi_nawamot_wuzunejufavo.pdfIn PDF document text
    • http://oblakova.ru/kirofavikakomavth.pdfIn PDF document text
    • http://zememor.sportsontheweb.net/barnett_vortex_lite_youth_compound_bow.pdfIn PDF document text
    • http://bhd-management.space/4331195324bfjuo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://de2ee6d5-caaa-4265-b15c-40100ab77d99.filesusr.com/ugd/d43733_7fb135e4c6ec43cb894f8fcf8adeb692.pdf?index=trueIn PDF document text
    • http://birukuf.onlinewebshop.net/lelatusokibuvulo.pdfIn PDF document text
    • https://12c48f50-3553-44c7-a31c-19fc5df83d07.filesusr.com/ugd/7e0eb0_116ec7c2e1f748dbbbecc3551dc80015.pdf?index=trueIn PDF document text
    • https://5de6e22f-064f-4859-b003-4eaa502c5056.filesusr.com/ugd/2609e6_2fabe9200f124b30b9ae84250294bd50.pdf?index=trueIn PDF document text
    • http://lojabupabavize.onlinewebshop.net/jinekigovibeg.pdfIn PDF document text
    • https://eed7fa7e-4f31-4ba6-8269-e73f07ac74c5.filesusr.com/ugd/93374d_9787d1348c41445ea07a9be336aae17e.pdf?index=trueIn PDF document text
    • https://00eaa6b3-f026-4720-b00f-fafb40066352.filesusr.com/ugd/d498be_f27082b672d84429920545e9ac1dc488.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_off0000ef40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF40 5076 bytes
SHA-256: 4500756e47518d7792facc25cc70f2e1ac771703ec16e819b3fde2403fc6707f
font_01_sfnt_off0001008b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1008B 10516 bytes
SHA-256: 4aea94e96107c1f3d08f8eff57575244e5e51d91e12836773dd8e191cd76a682