Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b4cfc738d2e6e84…

MALICIOUS

PDF

83.7 KB Created: 2021-10-08 18:28:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 6746e2235e2d0694946330a911d9945c SHA-1: 25560058cec713b8fe10bf3abaf38014da5db09d SHA-256: 5b4cfc738d2e6e840221e3c98a78d3a03f9f7c79b82f4eed5931608c987a0a36
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. The heuristic analysis revealed it functions as a link farm, embedding numerous URLs pointing to potentially malicious or disposable domains. The presence of external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' rule strongly suggest an attempt to redirect users to phishing sites or download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://cructi.ru/uplcv?utm_term=download+facebook+phishing+page PDF link annotation
    • https://sanaspinler.net/calisma2/files/uploads/ramafujin.pdfIn PDF document text
    • https://shiprapublication.com/uniformkontakt/userfiles/image/files/velulitokemije.pdfIn PDF document text
    • http://hiroshima-teishaku.com/userfiles/file/disewebi.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/8b2fe590287748b54bb8589ca912e7c5/lelilivowalu.pdfIn PDF document text
    • https://iaido-iaijutsu.ru/userfiles_exc/dovasavowudabumewev.pdfIn PDF document text
    • http://apartament-krokus.pl/userfiles/file/piruguwepoluseberuxat.pdfIn PDF document text
    • http://vietcem.vn/public/default/ckeditor/files/37862585306.pdfIn PDF document text
    • https://wic-net.com/userfiles/file/21742390061.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/1585811296.pdfIn PDF document text
    • http://sushigonewildtogo.com/uploads/files/23823670713.pdfIn PDF document text
    • http://drentmedischadvies.nl/uploads/files/mofaguzux.pdfIn PDF document text
    • https://ms02bet.com/contents/files/802889329.pdfIn PDF document text
    • https://lensmam.com/userfiles/file/tumodenokawawutoxojajija.pdfIn PDF document text
    • http://casaledellasignora.it/userfiles/files/galinulobon.pdfIn PDF document text
    • http://www.lebedosapartotel.com/data/yukle/files/43587010878.pdfIn PDF document text
    • http://kooijobs.in/ckfinder/userfiles/files/31946581925.pdfIn PDF document text
    • http://zensushialiso.com/uploads/files/33453714665.pdfIn PDF document text
    • https://bcm.es/files/galeria/files/tumikipagapitewu.pdfIn PDF document text
    • http://oguraclutch.cn/uploadfile/files/baroxumakotabusageke.pdfIn PDF document text
    • http://integrotech.eu/zdjecia/file/97539150682.pdfIn PDF document text
    • https://valerart.com/ckfinder/userfiles/files/lereduxiwod.pdfIn PDF document text
    • https://webshopplus.nl/app/webroot/files/userfiles/files/38727182373.pdfIn PDF document text
    • http://oroblupiscine.it/userfiles/files/naxumuke.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_off0000dd20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD20 11020 bytes
SHA-256: 1abdf2836de6a9f5489dd70f5ab7263ce02e2b1830e7674a00ff0e69182a8456
font_01_sfnt_off0000f64b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF64B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E5D 19068 bytes
SHA-256: ea106e17e9b690a8463e934d777d782c50e9d7841d8e6e50384cc7351bc79fa1