Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e8bc037206106af…

MALICIOUS

PDF

76.9 KB Created: 2021-04-06 17:43:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: a4a7fc9893ecf3474f9d5fa17ae2286b SHA-1: 400494bfca708354f9e02ddaf80c83cd33e6099b SHA-256: 4e8bc037206106af015936024f403094a6bf5ab3c1b166b3b3305653f9864584
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO spam operation. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and numerous external URIs point towards a malicious document designed to redirect users to potentially harmful content.

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://zajinet.ru/123?utm_term=okex+platform+review PDF link annotation
    • https://cdn.sqhk.co/kolokejo/gbwichf/best_classical_piano_pieces_to_learn.pdfIn PDF document text
    • https://cdn.sqhk.co/nomevagume/HVrYgfN/wolipaxedegefizagabexarib.pdfIn PDF document text
    • https://cdn.sqhk.co/dagedazi/5HCUjUC/after_world_war_2_the_automobile_quizlet.pdfIn PDF document text
    • https://xabisemegebo.weebly.com/uploads/1/3/4/4/134491474/tolatos.pdfIn PDF document text
    • http://natlab.ru/astrill_china_linkiyp28.pdfIn PDF document text
    • http://ita-bio.fun/40990279200u2jw6.pdfIn PDF document text
    • https://katolafafesol.weebly.com/uploads/1/3/4/4/134479470/60a766b.pdfIn PDF document text
    • https://cdn.sqhk.co/lulaxujik/LhdhcE9/23905466461.pdfIn PDF document text
    • https://cdn.sqhk.co/podizapexiv/ijOjeha/rivoniluwo.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/vavejijitatofu/38271176336.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eb197b41-b380-41e3-8e34-be18c082d99a/why_does_heat_burn_skin.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1c0deae4-110c-4b56-ba6f-3beaab7579a2/methods_of_biblical_interpretation.pdfIn PDF document text
    • https://7162f0c1-3bb2-4775-9ad2-1e34613fb889.filesusr.com/ugd/595093_8ac7b269450c4e76864d5b9944de5c73.pdf?index=trueIn PDF document text
    • https://edefa294-c65c-46c5-840b-8a4669b9fdfe.filesusr.com/ugd/e4a001_3aeeb2a19ac84680b90b8531c111942e.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a6bf0870-5f12-4cc8-b43e-d67edeed10f1/how_to_get_discount_on_dyson.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cebe1588-49d4-4da0-bd30-906be85ede08/rekesisi.pdfIn PDF document text
    • https://s3.amazonaws.com/vaxebisapesi/73051556369.pdfIn PDF document text
    • https://s3.amazonaws.com/rovuweraja/what_does_rainsford_do_in_the_most_dangerous_game.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9ad891e3-a8d0-4547-8937-cb3264ecc2dc/99255584876.pdfIn PDF document text
    • https://1639490a-f715-481e-9fb1-af38d332269b.filesusr.com/ugd/a59130_f6fae921bbad445a85f65f9933693851.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xugigabitulu/harry_potter_y_el_misterio_del_principe_libro_pasta_dura.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_off0000ee41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE41 5180 bytes
SHA-256: ced509cf99fa98fbf9cb148d01ccf2ffc92ce74dfda0d234ed5e5a36627ec3af
font_01_sfnt_off0000ffe5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFE5 11208 bytes
SHA-256: 29a7de67e46d27e406ad691c9a3f1ba82fdd0c587df86fbdf9cb5f06aac2e997