Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6d3da7e0ca71d47…

MALICIOUS

PDF

76.3 KB Created: 2021-03-22 02:41:03 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: c6c5b05dabf18b133c2ef5cc7637e21a SHA-1: b47c777e6394fc2b3cc73beff965c7032a8055aa SHA-256: a6d3da7e0ca71d47a5cb1c671affcbe49b4dc2f84ddef99360f731f6c01d5294
66 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, with a high heuristic score indicating it functions as a link farm on disposable hosting. The document body, though heavily obfuscated, suggests a lure related to "mixture and alligation questions and answers pdf" to encourage users to click the malicious links. The ML classifier also flagged this PDF as malicious with high confidence.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 4

  • 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://bologen.ru/award?keyword=mixture+and+alligation+questions+and+answers+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4481154/normal_5ff65ec0c8a20.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481520/normal_5fd0ec9d8967b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480598/normal_603872b33547f.pdfIn PDF document text
    • http://valuburikodajad.medianewsonline.com/wilcox_s_surgical_anatomy_of_the_heart_free.pdfIn PDF document text
    • http://zesegalos.scienceontheweb.net/doworefarojavomelodo.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420756/normal_600e23135ec50.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476601/normal_6047cff81a4ee.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/kozewuposoridil/13549310084.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1a4813a2-1cec-4cec-bc47-a6d70a0cd79b/vokoteloxuzafifukad.pdfIn PDF document text
    • https://184d393c-d2ff-49e5-bbcb-48626b1dbf88.filesusr.com/ugd/49be48_4a5abf806de94bccb2a27bd5acf386db.pdf?index=trueIn PDF document text
    • https://f4dd034e-00c7-465c-b850-fb2d75accad5.filesusr.com/ugd/769f78_b37b60a81e344e0880aee7aeb4294346.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/b1aef1bd-24d5-4396-8f4c-85ee9ba42857/92478635042.pdfIn PDF document text
    • https://s3.amazonaws.com/wexoteluwag/pizama.pdfIn PDF document text
    • http://tuzuxutetug.atwebpages.com/85319772090.pdfIn PDF document text
    • https://2f2ab42d-e0b4-4bd3-aa50-2430da1ff5fc.filesusr.com/ugd/eaf48f_5eac14149d254f0786a26df41badb701.pdf?index=trueIn PDF document text
    • https://92fed17e-af34-466b-b3fe-38cd9ef27699.filesusr.com/ugd/192d58_e3af44a189d64adea1d735bc4d58dd6e.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/daxemo/who_developed_modern_management_theory.pdfIn PDF document text
    • https://c7bff75e-0a19-4817-9d47-fca4cf08161b.filesusr.com/ugd/3b6424_168fdcc0d5874a9799dfae6ec90d636e.pdf?index=trueIn PDF document text
    • https://db532842-334f-4efb-8993-e67ec8f20ff5.filesusr.com/ugd/bc5be3_4d27fc96a26146c5bf947e13cdac388c.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/gosete/bomberman_pc_full.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_off0000edd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD3 5500 bytes
SHA-256: 8c0128a9771a5cdfa0e44a315be504606b073e5d0c22915f2b161b4130a315eb
font_01_sfnt_off000100c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100C0 10744 bytes
SHA-256: a6b23c9f600494fc1c87af8b0e3d02aa5426fc61ef9ce8fe5e2c536cd6b56d62

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