Malicious PDF — malware analysis report

Static analysis result for SHA-256 7bd57d6f6e909503…

MALICIOUS

PDF

82.5 KB Created: 2021-03-30 13:29:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 43933651f3077a2d31bb41bcf2938381 SHA-1: deb95f500569e8f70ca2b9c6cb7d101659b7aa5b SHA-256: 7bd57d6f6e90950310aad346e92c0ec4cec07bf0f7ed17af16e1b4596ca47d79
186 Risk Score

Malware Insights

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

The PDF contains numerous external links, identified by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically related to phishing. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a malicious document, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://xajibur.ru/wix?keyword=brenda+maze+runner+quotes PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4498994/normal_6044d69e07025.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453560/normal_6026b2ab92db6.pdfIn PDF document text
    • https://cdn.sqhk.co/sotisajen/gie7Qif/animal_colouring_book_apk_download.pdfIn PDF document text
    • https://cdn.sqhk.co/dufolatik/fZRjfjb/inflatable_water_slides_for_sale_ireland.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382972/normal_60387c90a7f9c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4410416/normal_5fff3e7c55e87.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4494160/normal_6062a0dadc127.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4453732/normal_5ff9fc4fa89cc.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375885/normal_6006369f5b03c.pdfIn PDF document text
    • https://cdn.sqhk.co/kufomopinu/fjojagd/mountain_bike_shoes_mens_clipless.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374521/normal_605039d80a340.pdfIn PDF document text
    • https://cdn.sqhk.co/kemuxilajig/cSahdtF/semeganurefotejugi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426060/normal_60143b3465c6d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4426828/normal_5ff3c6061047c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408583/normal_6035b631d7976.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://70848fb0-0fd0-490a-9360-2ffa38fc212c.filesusr.com/ugd/08e331_a4c00e8e29384d8b92c699f1af258a7b.pdf?index=trueIn PDF document text
    • http://pobabujotuv.epizy.com/completing_the_square_maths_genie.pdfIn PDF document text
    • https://0621cc9e-6449-4e8a-a8bd-baee9ad62a2c.filesusr.com/ugd/affb4a_a479e9d46f89401bae0c658862683abf.pdf?index=trueIn PDF document text
    • https://48e5b1ff-25fb-49a4-826b-3ad3f3a15688.filesusr.com/ugd/0d632a_5ac4f98932a34a17b23d6a8be948bb2a.pdf?index=trueIn PDF document text
    • https://9579f988-9383-433c-acf3-5fff76e0c882.filesusr.com/ugd/191a6d_bfddb20d2b734f35912042b14c50d41e.pdf?index=trueIn PDF document text
    • https://33c7e2ec-32fc-4676-a642-9d95a4379e01.filesusr.com/ugd/622218_e9414e2cdb5f4fc7a8b423d55f9866e0.pdf?index=trueIn PDF document text
    • http://vipoxegoto.rf.gd/11042887004.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_off000109e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109E8 5164 bytes
SHA-256: 21b28498e7b5cf8330fc1432d3ef43f2ba38638a29d84bfd37da9327de99ac0e
font_01_sfnt_off00011b60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B60 10064 bytes
SHA-256: 0b984eb58bf21645c6572d6b671bb2dae3542392b167e395d10d7273b5112d51