Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6d3921b68ac938d…

MALICIOUS

PDF

74.9 KB Created: 2021-09-17 17:08:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6f379fa32759b6dc77c30c524dfc2dac SHA-1: 6978f6ffa897969d1fe589e10f84b3ba21bcb49e SHA-256: f6d3921b68ac938d2695c08adbb3eda2c4e91b555821f6ee79b6b22025c07fa8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed for SEO manipulation. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The primary attack pattern involves luring users through deceptive content to external, potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://neonatal-surgery.ru/userfiles/files/78067019285.pdf In PDF document text
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/gebimilijogitoxezamopu.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/16141418a62d30---rerosikisamazine.pdfIn PDF document text
    • https://andymullinscommercial.com/home/andy/public_html/ckfinder/userfiles/files/84182308787.pdfIn PDF document text
    • http://www.cenlafilm.com/siteuploads/editorimg/file/64850665446.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613953069f514---fikulovipade.pdfIn PDF document text
    • https://frenstravel.com/assets/ckfinder/userfiles/files/feniregawob.pdfIn PDF document text
    • http://mazraeir.com/images/upload/files/14486562835.pdfIn PDF document text
    • http://primaria-ciocirlia.ro/media/file/xizinimare.pdfIn PDF document text
    • http://dongduong.net/Images_upload/files/rukatazazis.pdfIn PDF document text
    • http://kstarsmall.net/userfiles/file///sumawibelapen.pdfIn PDF document text
    • http://delannahotel.com/user_img/file/gitilobuzinoxu.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/fuwijonapotekuxolupi.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/1612edcf48067d---tawalavogi.pdfIn PDF document text
    • http://nj-rshb.com/v15/Upload/file/20219151726523414.pdfIn PDF document text
    • http://praconsulgroup.ru/pict/file/89113115168.pdfIn PDF document text
    • http://mgtuae.com/uploads/file/44008478793.pdfIn PDF document text
    • https://iuoshili.com/upload/users/files/bisenuvamonane.pdfIn PDF document text
    • http://worldnaturalfood.com/image/upload/File/xurefonoselaza.pdfIn PDF document text
    • https://gberwanda.com/gbe/useruploads/blogs/files/36999070248.pdfIn PDF document text
    • http://freestyler.cz/img/file/55013784201.pdfIn PDF document text
    • http://gardensyellowcab.com/admin/images/file/wajidebodevotes.pdfIn PDF document text
    • http://onlinecommerce.bg/uploads/pages/files/15777035121.pdfIn PDF document text
    • http://tandprotheses.com/ckfinder/userfiles/files/31647910061.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=connect+ps4+controller+to+tabletPDF 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_off0000c17b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC17B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d992.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD992 10524 bytes
SHA-256: 4c980a0e4ed68d2276e7aea7223cb872b51c16db596518690b18250f83c536c1
font_02_sfnt_off0000f185.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF185 17192 bytes
SHA-256: 714dd33a86600e000ee13690da13da2a93b80fa0f6ae8d161546396745666438