Malicious PDF — malware analysis report

Static analysis result for SHA-256 5ad994b9a679aa4a…

MALICIOUS

PDF

87.6 KB Created: 2021-06-02 14:32:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 5556c39168b6a968aeb887080d93929e SHA-1: 9883518f391c544ab43fd021c7bafb15d38a2d2e SHA-256: 5ad994b9a679aa4a3eccb0ce92b54adfcbb89992771ebe09e8efd37cc6b8fe8a
126 Risk Score

Malware Insights

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

The PDF contains an embedded URL pointing to 'synerhu.ru', disguised with a query parameter related to mortgage approval letters. Heuristics indicate this PDF is part of a link farm on disposable hosting, and ClamAV detected it as a phishing trojan. The ML classifier also strongly flagged it as malicious, suggesting the primary goal is to redirect users to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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 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://synerhu.ru/pbw?utm_term=what+is+a+mortgage+approval+letter PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4382429/normal_60524e0a5b86c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417216/normal_600dd1643b4b8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4456387/normal_5ff67590c6918.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391899/normal_604cf94370f61.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4489429/normal_5fc6158211706.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4374021/normal_5fe0ff0ae7668.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415936/normal_6038c2b716438.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369491/normal_6031f5bb43c43.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/1b7c2275-4035-459b-ab0c-5619795629fd/14985101256.pdfIn PDF document text
    • http://lekuzax.pbworks.com/f/ccf_probabilit_terminale_bac_pro_corrig.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/12956e11-241f-46a7-b2a8-0a576cf86bb1/how_to_set_a_samsung_air_conditioner_remote.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e0e065a1-9902-4ee0-b8ef-ee1c61716e8a/33241030069.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fad34729-8d03-46fd-9f22-f64fe99a39c3/sorowisegexafarekerenafa.pdfIn PDF document text
    • http://sazupamufode.pbworks.com/w/file/fetch/144477834/redugakajoxedof.pdfIn PDF document text
    • http://fepewuwakow.pbworks.com/f/rezevininifasuguxofixir.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/65d562a4-0d1a-484a-a9d3-c9889434d06d/what_is_the_best_bible_to_get_for_beginners.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1afd9d6a-8535-4583-be45-b36d8bc04b77/the_bluebook_a_uniform_system_of_citation_20th_edition_download_free.pdfIn PDF document text
    • http://bojirakaj.pbworks.com/f/evermore_beauty_and_the_beast_piano_sheet_music.pdfIn PDF document text
    • http://poxanoralanu.pbworks.com/w/file/fetch/144422763/vojir.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_off00011829.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11829 5304 bytes
SHA-256: 253feb922d7e434109878251e4790a9a6191de2bc7d99ac80890fd1ed082ec11
font_01_sfnt_off00012a1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A1D 11560 bytes
SHA-256: 7f3866441bafb2073521fafb24ca835a64df6bd8f3d4387e5a34d1c840a3d838

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