Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e731c94a2f9718f…

MALICIOUS

PDF

76.4 KB Created: 2021-03-06 03:19:24 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-20
MD5: 046ca73255c5f442a8d3e696005f7203 SHA-1: 81d829377aea454a8b4f6ddc9a862f4dc1dfe376 SHA-256: 4e731c94a2f9718fd947b6fc0b12cb55dccada810dd17b68b05fef1558b6aa2d
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan' and an ML classifier indicating maliciousness. The presence of numerous external URIs, many pointing to disposable hosting and exhibiting link farm characteristics, strongly suggests a phishing or malware distribution attempt. The document body, though heavily obfuscated, contains metadata related to 'wkhtmltopdf' and a title 'Tesis y estructura del texto argumentativo', which likely serves as a lure to disguise the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 5

  • 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 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://seumenha.ru/123?utm_term=tesis+y+estructura+del+texto+argumentativo PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4470981/normal_6014fef8897df.pdfIn PDF document text
    • http://ita-talia.fun/calibre_20_performancemtmft.pdfIn PDF document text
    • http://kipokefurur.mygamesonline.org/how_to_integrate_sin_x_squared.pdfIn PDF document text
    • http://vutunema.mypressonline.com/kuziriwulat.pdfIn PDF document text
    • http://9gusevshop.space/beer_pong_table_ideas_paintingrc1hp.pdfIn PDF document text
    • http://zonizubiro.getenjoyment.net/hot_caramel_latte_dunkin_donuts_calories.pdfIn PDF document text
    • http://meetsol.xyz/350659108771oyuw.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408703/normal_5febc080c2bee.pdfIn PDF document text
    • http://navalny.design/dozuvozizipo2ygta.pdfIn PDF document text
    • http://evromotors.net/merogegefazinedab92o3.pdfIn PDF document text
    • http://myluckywin.site/9476048491107r4x.pdfIn PDF document text
    • http://esclick.pro/sultry_summer_ben_ten_downloadlskqp.pdfIn PDF document text
    • https://binolopokam.weebly.com/uploads/1/3/1/4/131484395/031b243d0e389.pdfIn PDF document text
    • http://jabewes.medianewsonline.com/are_there_civilian_jobs_in_the_navy.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369158/normal_602458e051b34.pdfIn PDF document text
    • https://palajuwasodix.weebly.com/uploads/1/3/2/8/132815908/lobanasenevigo.pdfIn PDF document text
    • http://berkeciftci.net/tyler_dunne_bleacher_reportap3f5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4387408/normal_5ffa94b6abdc8.pdfIn PDF document text
    • http://netewe5.xyz/fofinasozarescr5p.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://vidugozu.atwebpages.com/nemefejakopesabebogekid.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7aed2e61-074e-4d03-ba74-1e56c83fa865/what_is_personal_accident_insurance_coverage.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/808ba67f-b896-4c6c-9041-2b98040d9b83/windows_10_for_dummies_free.pdfIn 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_off0000eb0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB0C 5436 bytes
SHA-256: 1d8e937582c12186a287ef54f33ae05fcd85082f73fa6486e576af682e20c260
font_01_sfnt_off0000fd87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD87 11424 bytes
SHA-256: 94ac613cf1622f66f6bee805feb4058c347ee8e868a8258b3d97dca5b5ffaf37

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