Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1cb7a2f01497b94…

MALICIOUS

PDF

69.7 KB Created: 2021-10-02 09:20:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 426c320dee8d31620fa83d7e1d26f94a SHA-1: 973b89ca69a348c9fb01e738c7ca7747b01c2283 SHA-256: b1cb7a2f01497b9445e49b68a9ffa8e1bf1ecea1c85ff546a0dcc074503ae22c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution intent. The PDF contains numerous embedded URLs, many pointing to disposable or suspicious domains, suggesting a link farm or phishing lure. The presence of external URI heuristics and the ML_NYX_PDF_MALICIOUS firing strongly support this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9959

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://ketchas.ru/uplcv?utm_term=best+friend+halloween+costumes+devil+and+angel PDF link annotation
    • https://dmshospital.com/mm_engg/files/2167774316.pdfIn PDF document text
    • http://mstreatmentadvances.com/userfiles/files/xikodawavix.pdfIn PDF document text
    • https://jecoexports.com/ckfinder/userfiles/files/pazuvutatefotirefuve.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16144265973095---ropomibavunegaj.pdfIn PDF document text
    • http://vietcem.vn/public/default/ckeditor/files/1942667425.pdfIn PDF document text
    • http://dkkarsin.pl/img/upload/files/tazik.pdfIn PDF document text
    • https://confidence-ist.mktechsol.com/ckfinder/userfiles/files/sexedexewidu.pdfIn PDF document text
    • http://gift-founder.com/archive/upload/files/ladefemajudixexabo.pdfIn PDF document text
    • http://creativetechno.in/userfiles/file/nekazunovobobe.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/b414c8f0cebce51842ea02d090b40b4c/pimarorizidad.pdfIn PDF document text
    • http://limeitec.com/upfiles/editor/files/5485755888.pdfIn PDF document text
    • http://www.thaitofu.com/image/upload/File/79492070389.pdfIn PDF document text
    • https://mingyi-lock.com/data/file/userfiles/files/25828271919.pdfIn PDF document text
    • http://newshop.jp/archive/file/zumas.pdfIn PDF document text
    • https://sopkambing.com/contents/files/16879504105.pdfIn PDF document text
    • http://duef.ru/public/file/nokipin.pdfIn PDF document text
    • http://laiyi-art.com/userfiles/file/jigonuvotetomanazit.pdfIn PDF document text
    • https://laughteronlineuniversity.com/images/upload/files/66859336400.pdfIn PDF document text
    • http://tcihk.com/userfiles/ponopabolodoterixiw.pdfIn PDF document text
    • https://rozynoklinika.lt/userfiles/file/penigujujuji.pdfIn PDF document text
    • http://euskararenginkana.eus/files/galeria/files/dijakiwizitu.pdfIn PDF document text
    • http://nsdadventist.org/FCKData/file/dapugodanazupotasojidox.pdfIn PDF document text
    • http://lyzebrno.cz/userfiles/file/zepazu.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://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_off0000ad61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD61 15628 bytes
SHA-256: c593c8c05061cded471b1c142049530fbc58998fff5de79ada378e784a06cb9a
font_01_sfnt_off0000d500.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD500 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED17 11228 bytes
SHA-256: 31854d41ece61c51d4f87f1be8bc5e07d4731dc46acd599158ad03e19b68a94d