Malicious PDF — malware analysis report

Static analysis result for SHA-256 de41bea891f80711…

MALICIOUS

PDF

78.7 KB Created: 2021-05-31 17:04:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: a78f51e80a477846b74448c0c99b9745 SHA-1: fc04fec9d9eaf9762643d564960b2c7a8df84509 SHA-256: de41bea891f80711dcecba2b5a52bb31a8504f530886afbe050813503240a552
226 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a fake browser/software-install lure. 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 0.9993

Heuristics 7

  • 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.
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://crysiq.ru/pbw?utm_term=how+to+verify+bitcoin+wallet+on+cash+app PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4380226/normal_604ee56422774.pdfIn PDF document text
    • https://xuboxale.weebly.com/uploads/1/3/1/4/131452808/basejiv_vilul_nadulepe.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4479224/normal_6018ebe9b8a5a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426960/normal_605a11966c7e9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375907/normal_5fe1081eca58b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451035/normal_60599f99bb7da.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410030/normal_606ea924ad2e4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4467043/normal_603c417aafe55.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4496146/normal_600f80ca1236c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459165/normal_60185605c9391.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489596/normal_5fea10109c2a0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4482027/normal_604db3337da5b.pdfIn PDF document text
    • https://vetaroxavobu.weebly.com/uploads/1/3/4/4/134441067/a86d3a8f4c389.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4446270/normal_5fd091974ad76.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450039/normal_602ffc25141a3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4492250/normal_600f4bf9c3b10.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4453560/normal_60aff7bc6b9eb.pdfIn PDF document text
    • https://zutijuxugovoxi.weebly.com/uploads/1/3/4/6/134684331/xijarenezafatef.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://jesababa.pbworks.com/w/file/fetch/144413847/what_is_the_difference_between_direct_and_indirect_object_pronouns_in_italian.pdfIn PDF document text
    • http://kekirow.pbworks.com/w/file/fetch/144411975/wenixaluveku.pdfIn PDF document text
    • http://visetululiv.pbworks.com/w/file/fetch/144415209/nuvipiduvupavejenapabuz.pdfIn PDF document text
    • http://jesababa.pbworks.com/f/nisawa.pdfIn PDF document text
    • http://lekuzax.pbworks.com/w/file/fetch/144414993/44500456403.pdfIn PDF document text
    • http://xifilipisi.pbworks.com/f/can_i_use_vicks_humidifier_with_newborn.pdfIn PDF document text
    • http://zopujoxobug.pbworks.com/w/file/fetch/144411441/how_to_write_a_break_even_analysis.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_off0000f494.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF494 5460 bytes
SHA-256: 8e8c8adac74c97b38bfe7c5745a57f28e8544381d787be344dbbaf22e76df342
font_01_sfnt_off00010736.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10736 11084 bytes
SHA-256: 402e1d4b8cda742fd00ed8105889843c910b68ae4340d6f3ba5ad28108fd2ef7