Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ecfb4c2f2579659…

MALICIOUS

PDF

89.1 KB Created: 2021-03-31 14:35:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: ad7e8f10196f078403abba973a08b002 SHA-1: 65e69905890f5d5578403ed7139c2383c8631ef3 SHA-256: 4ecfb4c2f2579659a1975815a3349cfc31293b88939f3e3d3f869ab3237469a1
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified by the PDF_SEO_LINK_FARM heuristic, suggesting a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly indicate maliciousness. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics point towards a phishing or malicious content distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • 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://botokaw.ru/award?keyword=sanskrit+etymological+dictionary+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4470962/normal_5fe93f80b47bb.pdfIn PDF document text
    • https://duxakezise.weebly.com/uploads/1/3/4/7/134713437/vovuvisetanova_befizoro_tozetimavidulin_rigojusebefun.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4372080/normal_6037c51ebdea0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475861/normal_6062a734d695c.pdfIn PDF document text
    • https://kodabovoxalomas.weebly.com/uploads/1/3/5/3/135340354/d60a621b08dc6b7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4473410/normal_5fd1b6b82ee66.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4490724/normal_5fe3fc6bc2eac.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490936/normal_601332c563d7c.pdfIn PDF document text
    • https://cdn.sqhk.co/lowixadoges/kheJVcT/94802490956.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478703/normal_5fe640a676acd.pdfIn PDF document text
    • https://cdn.sqhk.co/mewowoji/bbjbgja/miwatusonim.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384470/normal_600d002593531.pdfIn PDF document text
    • https://fezapatinegu.weebly.com/uploads/1/3/4/2/134266508/nakifuvezotel-gubos.pdfIn PDF document text
    • https://cdn.sqhk.co/waximanodif/yY0icif/m_s_c_ki_full_form.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451950/normal_605457edd28b6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4498404/normal_6018461cab22d.pdfIn PDF document text
    • https://lotaximadezepa.weebly.com/uploads/1/3/1/3/131379514/zunevetidorakijikivi.pdfIn PDF document text
    • https://zabaparadasikid.weebly.com/uploads/1/3/4/3/134317604/4695520.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450240/normal_5fd3af492df55.pdfIn PDF document text
    • https://cdn.sqhk.co/xojelumegasi/0Uzzgjg/55051084807.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/pevuwarobuvowa/zinabonomimavanijepe.pdfIn PDF document text
    • https://s3.amazonaws.com/dupula/what_is_the_objective_of_segment_reporting.pdfIn PDF document text
    • https://s3.amazonaws.com/kobivimelelo/guzotozilasewazaves.pdfIn PDF document text
    • https://s3.amazonaws.com/zafaronivaj/fogupav.pdfIn PDF document text
    • https://s3.amazonaws.com/bajuse/megodatip.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010f12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F12 5532 bytes
SHA-256: de1d4a73e04a22d21be46750d87915bf7f9a1735287bf38c7387c74af2849d16
font_01_sfnt_off000121d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121D2 11328 bytes
SHA-256: 166b9cb35390e2d86216b687e009350135adb4061af6b25923d3f4eee4df0932
font_02_sfnt_off00014865.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14865 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3