Malicious PDF — malware analysis report

Static analysis result for SHA-256 c61e3ba63f1e2721…

MALICIOUS

PDF

76.1 KB Created: 2021-09-22 11:50:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: acb2b58a51f58950505c9ebe49a2e68f SHA-1: ea6228785ad5814af572cf721b021f05587c8685 SHA-256: c61e3ba63f1e27213462d4441e2d0c3f39fe5915ba12bb55d996c5c3a7312e9a
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains malformed streams and numerous external URIs, indicating it is designed to redirect users to potentially malicious websites. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing or malware distribution lure, likely leveraging embedded JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://lonerangerfanclub.com/ckfinder/userfiles/files/79961770383.pdf In PDF document text
    • http://arabstina.com/ckfinder/userfiles/files/wujogakomipiji.pdfIn PDF document text
    • http://weforyou.it/userfiles/files/32035083666.pdfIn PDF document text
    • https://transport.frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/92291663251.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/kisaf.pdfIn PDF document text
    • https://igescanada.com/ckfinder/userfiles/files/90491978864.pdfIn PDF document text
    • http://turatabor.hu/media/gamexerisadasola.pdfIn PDF document text
    • http://studiotecnicopinto.it/userfiles/files/96479313938.pdfIn PDF document text
    • http://dohertylaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/meluteligefafafu.pdfIn PDF document text
    • http://saga.diamonds/uploads/ckfinder/files/zamivexarasavisatine.pdfIn PDF document text
    • https://www.mppoa.cloudlinesystems.com/assets/ckfinder/userfiles/files/nedikolofonazipo.pdfIn PDF document text
    • http://werkkledingverkoop.nl/images/docman/files/rarimijebusipipawager.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614ad5028e77d---xigino.pdfIn PDF document text
    • http://sweethomedelivery.com/ckeditor/ckfinder/core/connector/php/uploads/files/zosawafilukobil.pdfIn PDF document text
    • https://alixdemassy.fr/userfiles/file/jezefejapunenetewi.pdfIn PDF document text
    • http://highspiritsmusic.com/ckfinder/userfiles/files/rovafodijudozalelamurefow.pdfIn PDF document text
    • https://alternativi.brtim.com/uploads/wysiwyg/files/30935255313.pdfIn PDF document text
    • http://abarappresentanze.it/userfiles/files/zomabesonoxatonemiduje.pdfIn PDF document text
    • https://juhaszautovill.hu/userfiles/file/99153970280.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/9alprfk3b18352000ujng3kgpp/fepijoduwef.pdfIn PDF document text
    • http://apsencollege.org/test/fckeditor/file/38053455465.pdfIn PDF document text
    • http://inphuduong.vn/upload/files/6441516481.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=pokemon+omega+ruby+download+pc+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_off0000c211.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC211 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA23 18384 bytes
SHA-256: ff99432b97b25ea491f6f39305c2ebc2867d08fa1d69a5f21cf9084946149168
font_02_sfnt_off0001099a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1099A 11140 bytes
SHA-256: bef4e6e131d7f1d0ce4af30e8bff0244f1d1d597d141440721286cef72c7ad57