Malicious PDF — malware analysis report

Static analysis result for SHA-256 84843d8780d4097b…

MALICIOUS

PDF

69.9 KB Created: 2021-06-14 00:20:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 6313ed02b026f01806364fbb4f46ccb8 SHA-1: 8a7914dc5177a122760e60555bb554e6853f6f73 SHA-256: 84843d8780d4097bc938243d0bb02d0f3567ab862886f6e32ad8673dded7d50f
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of external links, identified as a link farm. The primary URL, 'https://cructi.ru/pbw?utm_term=fairy+tale+yiruma', suggests a lure, possibly related to search engine optimization or phishing. Heuristics indicate a mass external PDF link farm, with many links hosted on disposable domains, reinforcing the malicious intent. ClamAV and ML classifiers also flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://cructi.ru/pbw?utm_term=fairy+tale+yiruma PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4387562/normal_605cd23370ad5.pdfIn PDF document text
    • https://vugogirofezufus.weebly.com/uploads/1/3/4/3/134355312/9286491.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4410679/normal_6008a648288f6.pdfIn PDF document text
    • https://kaseloguxov.weebly.com/uploads/1/3/1/4/131406527/wawugu_doxifet_zameluxapakimas_ferum.pdfIn PDF document text
    • https://kasureketox.weebly.com/uploads/1/3/4/8/134856927/nebobujabe.pdfIn PDF document text
    • https://pupizotewijuguw.weebly.com/uploads/1/3/0/7/130775862/bd016146d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4480591/normal_5fcef4325065c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368770/normal_605a9a0502053.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445742/normal_6035959866119.pdfIn PDF document text
    • https://novunafa.weebly.com/uploads/1/3/1/3/131379228/jirigof.pdfIn PDF document text
    • https://gugakelu.weebly.com/uploads/1/3/5/9/135965899/7324116.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446921/normal_603549e68bb6d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481985/normal_5fc82c55af057.pdfIn PDF document text
    • https://saselafe.weebly.com/uploads/1/3/4/8/134894966/56211.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4457572/normal_600082910df8e.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/994e1f50-7b0d-451b-96b3-e0f5c41b76d8/1775032983.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/189442d2-69a4-4607-8cae-601bfbaeadd4/80694519644.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8dc200a4-12a7-4c5c-b5ae-76113addf5b9/hp_photosmart_d110_drivers_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2c33f271-d42e-48be-8f04-eeedf0a3b408/rinnai_electric_tankless_water_heater_for_sale.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fb170cf3-1bcc-4037-8cd7-a2ded58f62f8/raxininonasiba.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_off0000d619.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD619 4708 bytes
SHA-256: ba59eadc68ef59138f33019566d3b92f21d6a3422357b455e83e532628643ba1
font_01_sfnt_off0000e60f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE60F 10560 bytes
SHA-256: 752535c9fffa11a479cd30066b54dd0d2530f4aabb41730e0cd96d5bd576cb4c