Malicious PDF — malware analysis report

Static analysis result for SHA-256 835b1c5e19088082…

MALICIOUS

PDF

82.3 KB Created: 2021-03-17 06:33:33 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 18556b6426d3a7e090666b3ab9929472 SHA-1: ec24a5c684e6d7f7c0cf6f64d76c97f87ac9e450 SHA-256: 835b1c5e19088082c2832a2bff9b2ab94f59292893c61ae003a8dabb2d81937c
126 Risk Score

Malware Insights

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

The PDF file contains embedded URLs that redirect to external websites, one of which is identified as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document body, though heavily obfuscated, suggests a lure related to 'mechanisms of natural selection answer key' to entice users to click the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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 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://vilenefex.ru/123?utm_term=mechanisms+of+natural+selection+answer+key PDF link annotation
    • https://cdn.sqhk.co/bomoxale/r9Kgd16/tachyon_rods_canada.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415739/normal_6019ac9a6d332.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447465/normal_6047655fee208.pdfIn PDF document text
    • https://cdn.sqhk.co/videgogaf/y56icl7/woohoo_slots_play_free_casino_slot_machine_games.pdfIn PDF document text
    • https://cdn.sqhk.co/xegunorasu/iaihjcW/magic_color_color_by_number_online.pdfIn PDF document text
    • https://cdn.sqhk.co/woragumokewi/Ktijhjj/police_scanner_near_me_app.pdfIn PDF document text
    • http://apelsins.space/wojodexerigagozi1oqo.pdfIn PDF document text
    • https://cdn.sqhk.co/sitopizol/OKjgIMn/84133216955.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4449965/normal_5fc59d28860cb.pdfIn PDF document text
    • http://callup.today/just_mercy_book_club_questions0vqa8.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cb70cc59-2297-49c3-b7e2-2ac7e26e28d4.filesusr.com/ugd/4479ed_bcc804ff6a004727be8fd126ea632779.pdf?index=trueIn PDF document text
    • https://153f2bed-3501-4ec5-9468-ed1987511f6d.filesusr.com/ugd/f67134_bf356231454e4c459d9612bfe2db39d5.pdf?index=trueIn PDF document text
    • https://1ac5d900-0c69-4f12-8b1d-4e209472b8d2.filesusr.com/ugd/828753_cc89827ef84f455ebc2e9386518a4271.pdf?index=trueIn PDF document text
    • https://f815f12b-539f-4060-8ed9-abd2caada31b.filesusr.com/ugd/ceb2e8_0921dd84206e4c0f92438e61f2198bf5.pdf?index=trueIn PDF document text
    • https://dc58184e-bbba-402a-8e08-a55d552c8f3f.filesusr.com/ugd/0ebc1f_604d5143ce984c6498da56b4d16694b6.pdf?index=trueIn PDF document text
    • https://1cbf0fd9-62af-4102-a3dc-982f361539e7.filesusr.com/ugd/bfbc46_3907eee5cfed4bf7bce4220b07e172f4.pdf?index=trueIn PDF document text
    • https://5efcf519-4c71-4be9-a00f-e1d47ba804c5.filesusr.com/ugd/ebcc4b_c999a63434e349128e816d5012e1eab0.pdf?index=trueIn PDF document text
    • https://5e0c4d4d-41f9-428c-9564-b93e7cff6769.filesusr.com/ugd/510691_ec1a75ebba7746acab0e439243268c94.pdf?index=trueIn 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_off00010529.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10529 5384 bytes
SHA-256: ba6daee4a7ffe1226dd63b90d7a894c2688122334ede7948c4c56e55844606ec
font_01_sfnt_off00011776.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11776 10780 bytes
SHA-256: 0f1dd0f3a7227c8808b417f2438a0c2d41d2ddc0a42d3c184a5a4a56d0a84512

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