Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a1033b6baaf02f0…

MALICIOUS

PDF

82.6 KB Created: 2021-06-02 05:40:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: 1213e33f8b54458f3bf6bbf237370f5a SHA-1: 8a750b8a38bfb9c2a49c0425689d823129551cbc SHA-256: 4a1033b6baaf02f05f25805d5b853fa106e14544ad7d9a0a07be6fd16808b7ee
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://leonvi.ru/wb?keyword=how%20hard%20is%20the%20a+%20exam PDF link annotation
    • https://pigofularujatuf.weebly.com/uploads/1/3/4/3/134360020/1279446.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4443824/normal_606459c895e32.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421040/normal_606e1cdb7f768.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423171/normal_600c6d9c91e50.pdfIn PDF document text
    • https://duduzigofusu.weebly.com/uploads/1/3/2/8/132815892/37f3626bf3a.pdfIn PDF document text
    • https://gumomukus.weebly.com/uploads/1/3/4/4/134435284/8885547.pdfIn PDF document text
    • https://nanuvofekoredam.weebly.com/uploads/1/3/5/3/135385966/nuvukajobuke_sikopironoke.pdfIn PDF document text
    • https://bofufawikifof.weebly.com/uploads/1/3/4/2/134235483/4f401a6d3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4495059/normal_5ffa36812ea60.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4449984/normal_5ff758bcdd24e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369640/normal_5fedd601439e6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4424024/normal_5fe2e709952eb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475194/normal_603604efae04c.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
    • http://lekuzax.pbworks.com/f/reading_inca_history.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9b59a0aa-ba0c-4495-b29e-64a47fde1499/halo_bassinest_swivel_sleeper_bassinet_essentia.pdfIn PDF document text
    • http://jebusolole.pbworks.com/f/wumozib.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9a48d601-d66c-4d32-ac35-fd6ae8c1bf95/cunto_es_un_metro_cuadrado_en_milmetros_cuadrados.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bf8f131d-4942-4a1b-a27a-3f3c4d904d20/the_hellbound_heart_book.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/47ef54d8-fd5c-4eee-87d6-c07e8108cb5b/zuwisozawibifojofomatepow.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d7a9c3bf-564c-4e58-a0ac-607e406f9c25/introduction_to_genetic_analysis_11th_edition_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cd537219-9f30-4fe5-ba89-6f56752f0a4f/25820389270.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_off0000fa2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA2B 4836 bytes
SHA-256: 4670e99adc281510ed402f46fb4f8ffff7dbc62946bdd07e04b0b7569f1d9574
font_01_sfnt_off00010aa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AA9 10760 bytes
SHA-256: ea157acf2187fec11589851914995ebc869560965c793cf793f663c26310a61f
font_02_sfnt_off00012ec1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EC1 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c