Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5aaa7b9cb8f8905…

MALICIOUS

PDF

82.3 KB Created: 2021-09-09 13:03:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: cf0b1625bbe053fb04feed25e9e38b29 SHA-1: 2af7e025317a9ba3af4e56ad8c7b9375bda74b7c SHA-256: b5aaa7b9cb8f89050b4ddc65416cb5f28bda9fc3a90cb01896df381272abe14b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to disposable hosting and are structured as link farms, a common tactic for phishing or distributing further malware. The presence of external URI heuristics and the 'PDF_SEO_DISPOSABLE_LINK_FARM' firing strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pistant.ru/uplcv?utm_term=tabla+de+densidades+de+liquidos+pdf PDF link annotation
    • http://khacvietlaser.vn/public/images_news/files/4760696560.pdfIn PDF document text
    • http://highlevel.pl/userfiles/file/kufos.pdfIn PDF document text
    • http://doubles301.jp/files/ckeditor/files/1996899520.pdfIn PDF document text
    • https://heuresromantiques.com/upload/files/37372679659.pdfIn PDF document text
    • https://stallion-international.com/userfiles/file/6780498311.pdfIn PDF document text
    • https://mobilaide.com/upload/editor/file/jitapumiruj.pdfIn PDF document text
    • https://foursservices.com/nbloom/fckuploads/file/wuxerepasajerukogegimuvir.pdfIn PDF document text
    • http://www.libroparlatolions.it/backoffice/ckfinder/userfiles/files/8902493072.pdfIn PDF document text
    • http://www.almansori-ye.com/almansorifiles/files/nuxoguzarizemovixugiwax.pdfIn PDF document text
    • http://mim2010.ru/userfiles/file/9074980681.pdfIn PDF document text
    • https://discovercefalu.com/_data/images/file/lexebozosinuvasamuxaw.pdfIn PDF document text
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/2ebjen7ngcdtlj71v1qpqobo83/bawazovomapex.pdfIn PDF document text
    • https://sokolzgierz.pl/web/uploads/files/27280829511.pdfIn PDF document text
    • http://laconchigliacasevacanze.it/userfiles/files/kijugegekob.pdfIn PDF document text
    • http://altinay-law.com/images/file/wevozasekidu.pdfIn PDF document text
    • https://tecnibat.net/uploads/archivos/fabokuzizupafimopiji.pdfIn PDF document text
    • http://kleinschadenexpert.de/userfiles/file/sudezimotefedome.pdfIn PDF document text
    • https://zenmobile.in/jaipriyart/uploads/files/48048811926.pdfIn PDF document text
    • http://arucax.am/user_images/file/14788159701.pdfIn PDF document text
    • https://denizlihorozu.com/resimler/files/57289426054.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/11c8f7ab53b74394bb6efcd843c21ce8/vuxinelenukelubiluz.pdfIn PDF document text
    • http://s292376414.onlinehome.fr/datas/imgmail/file/4486134041.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_off0000d8ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8FF 10644 bytes
SHA-256: 59f19537a9d2808b98c009bcc0ba14048fb57c8c6f3e81b0db7131cb8247019e
font_01_sfnt_off0000f0fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0FA 19840 bytes
SHA-256: 480b6c70877d9125a94cae6d8445c0fe1e1051042f84a7ccdc0215c7fdc5ef88
font_02_sfnt_off00012370.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12370 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1