Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbb1ec83772ff8f2…

MALICIOUS

PDF

73.7 KB Created: 2021-09-18 04:20:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 71303a395e65583d9858ed9b5a1ace32 SHA-1: c3ea5ce1d2c77807f26da44f6c6637365cd5d1c7 SHA-256: cbb1ec83772ff8f205bf63dbbd79c929768e502bb5085c1ba1b68e417ea1aca3
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript, which is a common technique for executing malicious code. The PDF also features a large number of external links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to distribute malware or facilitate phishing. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://inwebjor.ru/uplcv?utm_term=android+tv+app+design PDF link annotation
    • https://sportnazona.bg/f/uploads/files/45304389307.pdfIn PDF document text
    • http://odontotecnicacoop.it/userfiles/file/fewewuvefodanikulonipoxov.pdfIn PDF document text
    • https://luxesystem.site/js/ckfinder/userfiles/files/jikubiwisura.pdfIn PDF document text
    • https://www.groupe-coelho.fr/ckfinder/userfiles/files/81448324357.pdfIn PDF document text
    • https://penal-garazh.ru/files/mitanuwe.pdfIn PDF document text
    • http://thebeautyofdesign.nl/ckfinder/userfiles/files/wijaxenagupogulerix.pdfIn PDF document text
    • http://etpatatietpatata.com/userfiles/files/50477715959.pdfIn PDF document text
    • http://elrey-uslugi.ru/media/file/9167072268.pdfIn PDF document text
    • http://miskolciharsona.hu/pictures/file/nanikevozeveja.pdfIn PDF document text
    • https://thietbixanh.net/uploads/files/nejujetiminidino.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/161451eb8bccb8---44166358051.pdfIn PDF document text
    • http://canigrup.com/userfiles/file/mafaliviperuwilekafibuz.pdfIn PDF document text
    • http://kingtonkatsu.com/uploads/files/xekedawas.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/c8457d47019a141c0d44ec31ecff3ad8/81950423762.pdfIn PDF document text
    • https://myagenda.myagenda.cz/pictures/editor/files/fadolibanifinefode.pdfIn PDF document text
    • http://immodraft.de/images/architekten_agentur_images_/file/53740171828.pdfIn PDF document text
    • http://chithanhplastics.com/uploads/userfiles/file/povaweduzadexiwoto.pdfIn PDF document text
    • http://coyada.com/up_images/up_images/kekutivoke.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131670c26a99---ratutavakiwil.pdfIn PDF document text
    • https://kaplaitalia.it/userfiles/files/lotesinoke.pdfIn PDF document text
    • http://podhoru.cz/userfiles/file/nijiletaxir.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/jekaku.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_off0000bee7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEE7 10568 bytes
SHA-256: 8d407e686def244b1a3f0ec2bd8e641e571e4cf8797db4e633ff4e4a687f5a9f
font_01_sfnt_off0000d6f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ef0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF0A 16944 bytes
SHA-256: a5208e72a4bb2a340b56d42967af96a206a4c6d792f23bc0e2ff4585244f58e1