Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc3f2a327c75b919…

MALICIOUS

PDF

82.3 KB Created: 2021-03-26 18:45:39 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 4b3dfa6d2d668bc8181ba27dffc7fe8b SHA-1: 4badefa781a76e63b8439be79e7c1c1bf9bd2b74 SHA-256: bc3f2a327c75b9199d09ee4216a77063b2012f8b7f6c0d42c56c2f48195de37b
186 Risk Score

Malware Insights

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

The sample is a PDF document that contains a large number of external links, many of which point to other PDF files hosted on disposable or suspicious domains. The heuristic 'PDF_SEO_LINK_FARM' indicates a deliberate attempt to create a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://fokemale.ru/123?utm_term=adding+and+subtracting+fractions+worksheets+9th+grade PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4367952/normal_5fda402c7804f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4452837/normal_5feb161c5714b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4498971/normal_60479c0c1edf8.pdfIn PDF document text
    • https://jelakuge.weebly.com/uploads/1/3/1/8/131856802/puxanisibevuzupukaba.pdfIn PDF document text
    • https://vafukomoruf.weebly.com/uploads/1/3/4/8/134862603/6712929.pdfIn PDF document text
    • https://cdn.sqhk.co/rokabumake/gi98Tgg/10187715984.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4499005/normal_5fe06c2f985a7.pdfIn PDF document text
    • https://voselorijovun.weebly.com/uploads/1/3/4/0/134041736/b50f2.pdfIn PDF document text
    • http://desajegurake.scienceontheweb.net/slavery_by_another_name_book.pdfIn PDF document text
    • https://waboralitenir.weebly.com/uploads/1/3/4/5/134504299/c0d026b1c3.pdfIn PDF document text
    • http://basidugom.mygamesonline.org/dress_design_sketch_book.pdfIn PDF document text
    • https://cdn.sqhk.co/kapimetavis/iejcaP5/wodowo.pdfIn PDF document text
    • http://vuzuwul.getenjoyment.net/32537299256.pdfIn PDF document text
    • https://wetusaseri.weebly.com/uploads/1/3/5/2/135297966/visarado_geduzojadigulo.pdfIn PDF document text
    • http://waxedeb.getenjoyment.net/levekir.pdfIn PDF document text
    • https://cdn.sqhk.co/bodegife/mjfiieI/greenhouse_poly_sheeting.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/897ed563-221f-4eec-bcde-af11e6c61274/13134209239.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e50402c1-9e95-4721-8e70-2ee964fb6f1b/troy_bilt_3100_psi_pressure_washer_pump_head.pdfIn PDF document text
    • http://tiredosutozol.atwebpages.com/aday_retmenlerin_okumas_gereken_kitaplar.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fda46895-094e-43e8-86ce-f0ea67f2cf72/excel_if_then_else_function_multiple_conditions.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/62a20f76-bf3f-4c8c-a433-ce1b86bd0897/ghost_of_spirit_bear_chapter_2_summary.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7f6ccc1b-8ce7-4746-b215-7b63a6c8e014/snow_white_and_the_huntsman_2_full_movie_download_filmyzilla.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ea065896-6392-4165-af6f-b24bbd5b2f91/75909907834.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1d425119-4bef-40fb-9bb8-8c08ad986eda/the_lively_art_of_writing_ebook.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_off00010040.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10040 5692 bytes
SHA-256: 37d11410c38f7a0137b9519dbf630d91c10ca6d5a57dd0f109ecfa1f5ed1a228
font_01_sfnt_off000113af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113AF 11392 bytes
SHA-256: a78f5feb919847e11811c939461900b4bbae6f8a36e0f0e02f002c13abe568ce