Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fefadc56bd6716c…

MALICIOUS

PDF

71.2 KB Created: 2021-06-10 10:48:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: e4e8d253347631a0a444f6d15aa3d325 SHA-1: 436b1661ddbde3c4300921d722d0b8f4963ddbdd SHA-256: 4fefadc56bd6716c33e60a1c652d120203e0261b05439c5dc15d597a08b9ebd3
136 Risk Score

Malware Insights

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

The PDF contains an embedded URI and a heuristic firing for a redirector link, both pointing to 'https://nomylo.ru/wb?keyword=physics%20for%20scientists%20and%20engineers%203rd%20edition%20giancoli'. This URL is presented as a lure for a technical book, indicating a phishing or malware download attempt. The ML classifier and ClamAV detection strongly support the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://nomylo.ru/wb?keyword=physics%20for%20scientists%20and%20engineers%203rd%20edition%20giancoli PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4421937/normal_60be6d56f3dcb.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4461204/normal_5fe5571a7951c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376875/normal_5fe9727b59d50.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481055/normal_5fff1ef2f2c31.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454164/normal_5feb23a61f516.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/a4ba08e0-b1a5-4449-a194-a3719f3a97e0/bodixuzutukekudotozuro.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/79f76a09-b4df-4868-885b-9c5dfda4386e/fundamentals_of_english_grammar_fourth_edition_answer_key.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/44647575-82b0-4ecb-b4f7-bdc297313351/crazy_love_francis_chan_book_review.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0e997022-9515-436b-bd8b-0b30d9bb0131/amazon_computer_books_for_seniors.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f47d24c0-1685-407d-8112-8658e2dc438a/crossfire_series_books_similar.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/44311ca3-a7fd-4686-9396-b3d5fa4cbc3c/o_que_significa_proponente.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f64206eb-b774-4a70-8cd1-8ab1a53f4660/32292253718.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8a987a8c-7123-4be6-8f23-8c808cedeb16/21303838331.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f74b3cbd-4d05-49fa-9286-8e7f12c66107/dark_heresy_character_sheet_editable.pdfIn PDF document text
    • http://sujagajo.pbworks.com/w/file/fetch/144592725/52891402325.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9f6b6d9e-e004-4f46-830c-879640bec3a6/the_hobbit_release_date_book.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ef9c7222-db43-46ec-a33b-938e66847095/gunvault_minivault_reset.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4a077435-ceca-4917-8f3b-e32133a4117f/77789275125.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ae818ce0-e1ca-4cc5-82eb-1d5cb017d87b/best_casio_tough_solar_watch.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fd2f5e27-9202-42fa-be48-40eefad5fdcf/24344611617.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0a84a43e-cdbf-43b3-8256-9a328d8e7557/best_spoken_english_book_in_telugu.pdfIn PDF document text
    • http://fosirodovo.pbworks.com/w/file/fetch/144453309/24996565610.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1438ece4-cc94-4485-b826-de84d71ae8f9/hp_c7280_printer_ink_system_failure.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_off0000da8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA8B 5548 bytes
SHA-256: 0725166977c7a2d61b5e425c9281aed7861df58f73044783cc62b663fad010c2
font_01_sfnt_off0000ed72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED72 9772 bytes
SHA-256: b74fc6e019b041a8d127132c2fe73f2fc8927372309f36617383a7b52beaef85