Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd85c99022264bcd…

MALICIOUS

PDF

68.6 KB Created: 2021-09-25 19:46:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b32fa8cc9b9f0f07c8bd50c2480e8d46 SHA-1: c837c737e3d769c1a066ebd50b3614eb0b5cbfff SHA-256: cd85c99022264bcd2c3f635c0000a86b039a570e40672630a61b6b186b792c0b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many of which point to other PDF files on distinct domains, indicating a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this is a tactic to obscure malicious intent or distribute further content. While no scripts were explicitly extracted, the nature of the embedded URLs and the link farm structure points towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

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://martensmgt.com/business_school/uploads/file/kiguxavuxifezapifatoru.pdf In PDF document text
    • http://cuspsurgeons.com/userfiles/file/38073386730.pdfIn PDF document text
    • http://epmresearch.org/userfiles/files/faxudoj.pdfIn PDF document text
    • http://chroscina.com/userfiles/file/sibizimirosanuxuwa.pdfIn PDF document text
    • http://photou.cc/ckfinder/userfiles/files/40000248678.pdfIn PDF document text
    • https://www.mds-horizons.com/upload/files/sepuvoduzikov.pdfIn PDF document text
    • http://kqcme.yiaiwang.com.cn/upload/files/18576560696.pdfIn PDF document text
    • https://fsreloading.com/userfiles/files/ritibujekifuvuwujaz.pdfIn PDF document text
    • https://www.clinicaepilepsia.cl/ckfinder/userfiles/files/57701721309.pdfIn PDF document text
    • https://motodubai.com/uploaded_images/files/35962965163.pdfIn PDF document text
    • http://rtm-plus.com/ckfinder/userfiles/files/mupakofak.pdfIn PDF document text
    • http://www.psychophonie-tarbes.com/ckfinder/userfiles/files/roxijorosulozojununof.pdfIn PDF document text
    • http://ccswcd.com/userfiles/file/18127506386.pdfIn PDF document text
    • http://www.oomewatersport.nl/upload/files/66959487274.pdfIn PDF document text
    • http://roosprommenschenckelfoundation.nl/userfiles/file/95589918007.pdfIn PDF document text
    • http://affordableadobe.com/ckfinder/userfiles/files/67900788620.pdfIn PDF document text
    • http://farmaciacogliate.it/userfiles/files/zeduk.pdfIn PDF document text
    • http://a2kat.ru/userfiles/file/21888432022.pdfIn PDF document text
    • https://soudurelauziere.ca/upload/editor/file/20503596030.pdfIn PDF document text
    • http://clinton.abwingsmd.com/uploads/files/firapawegavikaxuvukiso.pdfIn PDF document text
    • https://mbzl-pro.xyz/web/img/podborky/files/82110275318.pdfIn PDF document text
    • http://gopherandsquirrelcontrol.com/admin/images/file/padufuwujisog.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614665f5d0c23---fajuxawi.pdfIn PDF document text
    • https://longhoang.vn/upload/files/sikonizugofoberixiv.pdfIn PDF document text
    • https://jagamimpi.info/contents/files/pisekikag.pdfIn PDF document text
    • https://thaibamboorestaurant.ca/phpsites/bard_ford/uploads/file/benosuvo.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/mee649ojdincssubmlf0iej19c/26846862718.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=9+movie+freePDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b2d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2D5 14560 bytes
SHA-256: 98b0fc571af4331d97c508b069cd43cdcb03a8bc2aece1ebfa15cf43a33b4401
font_01_sfnt_off0000d738.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD738 9936 bytes
SHA-256: 50206335b5239565700ac9307193bff81d2c108ecdcf9cdb4d48a80a582440f8
font_02_sfnt_off0000ed38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED38 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1