Malicious PDF — malware analysis report

Static analysis result for SHA-256 21cf5aae32aadccc…

MALICIOUS

PDF

113.5 KB Created: 2021-05-18 00:52:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: f4b4a9fde167dd49e650485406ad221f SHA-1: eb9c631bcf396b6339fde8d831d34bd61a9e6553 SHA-256: 21cf5aae32aadcccbae9a2fd77bc4826e6d2614556f26bdf18120fa297548a0f
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to disposable hosting, suggesting a link farm or SEO spam operation. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were extracted, the PDF structure and embedded URLs are indicative of an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://nipisod.ru/strik?utm_term=quienes+fueron+los+5+primeros+presidentes+de+colombia PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4380680/normal_602af971c53e8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4372753/normal_600eaf6ba765a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425916/normal_5fd2a1135c854.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478947/normal_6046ba3ba4c3c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427506/normal_605838871814c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465388/normal_601234e0d0a93.pdfIn PDF document text
    • https://bipixexomalexu.weebly.com/uploads/1/3/4/3/134349320/631b0bf8c63.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4449774/normal_5fcd6f284781e.pdfIn PDF document text
    • https://xuxukogizi.weebly.com/uploads/1/3/5/3/135320654/06ba1a5.pdfIn PDF document text
    • https://migobajiker.weebly.com/uploads/1/3/5/3/135390735/vepofifalerozupiwaf.pdfIn PDF document text
    • https://tobivuzulukimu.weebly.com/uploads/1/3/1/3/131384599/4372298.pdfIn PDF document text
    • https://tivexafo.weebly.com/uploads/1/3/4/3/134348633/fomiwe.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489607/normal_6064bf9b6fa63.pdfIn PDF document text
    • https://duxuremi.weebly.com/uploads/1/3/4/6/134623812/kobaxelisugu_vizuzas_rowis.pdfIn PDF document text
    • https://diwekivoveludu.weebly.com/uploads/1/3/5/3/135313391/ditatumos.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/a3e65e3d-6b63-457d-a837-2e46d907b7f3/writing_with_style_trimble_chapter_3.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/96540c99-2a89-46bc-a845-09a854ceeda3/lepudegafolurizevakijitol.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/339ea25e-6eca-43db-b068-3a17117bfbbe/1738312050.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7a94b7d8-de76-4e48-8e09-5612c0130870/volume_formula_for_half_a_sphere.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/db7bb6b7-d0ce-4df3-aba4-cc6d252f15e5/fazujefepovemovemuxopenik.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/30340ed3-6c48-4f60-8a2d-6d0bd089677a/zoom_h4n_pro_battery_life_phantom_power.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/257f4350-0f78-4248-8336-1de96c2b4876/gapik.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_off000179b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x179B0 5624 bytes
SHA-256: 25ada2be297866efed86caba5e3c808a5b64f1ee3dbfd0728ba5ecb634b52c40
font_01_sfnt_off00018cba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18CBA 12924 bytes
SHA-256: 85748e7f9e059a070f024f1c38dcb4a2ec608b2b484f0017f3909eecc19cc37d