Malicious PDF — malware analysis report

Static analysis result for SHA-256 21279fb5f68bbb63…

MALICIOUS

PDF

90.2 KB Created: 2021-06-09 12:38:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 00b35b1edc2a6474de313f7aa7130473 SHA-1: 026cd4d5f24d8b8d0b9593162d1b6a7700375dcc SHA-256: 21279fb5f68bbb635065b654bd3bbea447e13075bcb8d21f09b8a128989837fd
186 Risk Score
Tags
free-cdn-ebook-manual-lure

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://cructi.ru/pbw?utm_term=algebra+1+end+of+course+practice+packet+answer+key PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4405179/normal_6052ed1ecaa59.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464522/normal_60547ac92da3e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4497370/normal_5fdafeb4b69dd.pdfIn PDF document text
    • https://nakumupapetiz.weebly.com/uploads/1/3/2/7/132741615/ruvojezovi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4474985/normal_605b2420d9344.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365594/normal_5fe966bc07ce1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419002/normal_6045f4b590381.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4381748/normal_5fca2790c63e0.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4372354/normal_6006a98414af0.pdfIn PDF document text
    • https://gesaleku.weebly.com/uploads/1/3/4/6/134694927/55a0805c0f39.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366011/normal_6012988b4d36d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375077/normal_603e9ae399944.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4425209/normal_5fee986b13f6c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375077/normal_6005abaa43b9c.pdfIn PDF document text
    • https://mezepimera.weebly.com/uploads/1/3/4/8/134860759/9424430799b9d.pdfIn PDF document text
    • https://fexinunob.weebly.com/uploads/1/3/4/4/134432760/ef7883f80b881.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4493597/normal_60beb315889f4.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://wodupabizel.pbworks.com/f/21003122566.pdfIn PDF document text
    • http://zikasamu.pbworks.com/f/monibifixatej.pdfIn PDF document text
    • http://mokapuv.pbworks.com/f/6451883540.pdfIn PDF document text
    • http://lopofemusun.pbworks.com/f/el_sobrino_del_mago_resumen_por_capitulos.pdfIn PDF document text
    • http://tazijebep.pbworks.com/w/file/fetch/144419616/21294455551.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_off00011d55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D55 5764 bytes
SHA-256: 6cfce1712d0360b9f2d2c9b51b71dc44b5b77f73b1e1d9bec47fa9ab458b8c81
font_01_sfnt_off00013128.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13128 11840 bytes
SHA-256: 597bba0174fb04feff09548b03a1dfcdd12e9d5d953d2e3eb627f46a95680787

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