Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4b54bd1d9bc51ff…

MALICIOUS

PDF

78.0 KB Created: 2021-03-31 21:48:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 20e86aea1526745badca1f298b956de3 SHA-1: 95c0ea7a59c587b4a6d2bbc66af487cd7a0c01d2 SHA-256: a4b54bd1d9bc51ff381593f0145ef1ebe325766b09f716aef25da157641656d1
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable hosting, suggesting a link farm or SEO spam operation. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were directly extracted, the PDF structure and embedded URIs are indicative of malicious activity.

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://nipisod.ru/award?keyword=all+animals+photos+with+names+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4487424/normal_6036233553eb0.pdfIn PDF document text
    • https://cdn.sqhk.co/nomazotesi/biisjb4/andhra_mess_tamil_full_movie_free.pdfIn PDF document text
    • https://wubudebekezame.weebly.com/uploads/1/3/0/7/130740051/cb4e91690.pdfIn PDF document text
    • https://kimilirakafame.weebly.com/uploads/1/3/4/6/134659192/padiritukagokiladup.pdfIn PDF document text
    • https://cdn.sqhk.co/zumedizojas/bmhhjia/tuzowas.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4447884/normal_5ffdfd32562c6.pdfIn PDF document text
    • https://cdn.sqhk.co/jogepirar/hbL3ONs/34087562986.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/10d84296-cd7a-4aef-b005-a84fa04a81f1/98588144774.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8fb67df0-d3f1-4c62-be34-980a9a5fa918/pdf_python_for_dummies.pdfIn PDF document text
    • https://2b08c346-38d8-4763-b559-bb9d4fff2313.filesusr.com/ugd/40c9d6_2d9891de165743d19bedccf2aef0afbc.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/552054a0-8b49-4afa-9965-a6ed4a3f39bb/rebizetoxamajeger.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d37c6fc3-dffc-4f8f-aaba-0e8353cbcc21/78483914646.pdfIn PDF document text
    • https://6090ae5c-070c-4b50-bfd2-11a66789f099.filesusr.com/ugd/83cce3_002a9da265fb404facc5e19bdf35344b.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/df0c4b92-8a72-4328-8e3a-e69b52b2d2dd/padumutuwesotitivamafaru.pdfIn PDF document text
    • https://f89b8795-a90f-4359-81e0-6309601a98d9.filesusr.com/ugd/8e7730_e3616429a2cc443a9178b90520f2dab7.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a0426323-b9c1-469a-8f81-4682d0b9b298/kowozowajutew.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fbbebbf1-21ad-4751-912b-cf8b2f343a93/samsung_nu7100_43_inch_weight.pdfIn PDF document text
    • https://933527c5-e005-4225-a3aa-05fee46c7696.filesusr.com/ugd/b51dd5_951580a6ac9446e8974664f54e3a3bbc.pdf?index=trueIn PDF document text
    • https://d896c2b7-539c-4146-aa8a-b39d26e096d8.filesusr.com/ugd/a98ecc_eebcb529b6c54c388c045d21458c5ca1.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_off0000f3e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3E1 5264 bytes
SHA-256: 8d5d65a01343011f303f8d2a9a9c281d8e6ee6697f5f170137d322ea92892c87
font_01_sfnt_off000105bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105BD 10940 bytes
SHA-256: 78569be0f5ea1f6910fd30b477f4ac6387034a153b3c08f682e44ea0b8d2437f