Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1059c4ac5d88343…

MALICIOUS

PDF

81.3 KB Created: 2021-09-18 12:08:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 0517e71ec436fb652091420f1191be00 SHA-1: 2a80c4fa0fc5bee71ce866629ac171e930cbb44b SHA-256: a1059c4ac5d88343da42d27c50c804e0f6244af81879a0186d69549280ae267e
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF containing embedded JavaScript and multiple external URIs, flagged by ML classifiers and ClamAV as malicious. The 'SE_CLICKFIX' heuristic indicates the document likely instructs the user to press Win+R or paste a command, a common social engineering tactic to bypass security measures and execute a payload. The embedded JavaScript and external links suggest the document's primary purpose is to download and execute a secondary stage.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • ClickFix social engineering attack high SE_CLICKFIX
    Document instructs the user to press Win+R or paste a command into a terminal — consistent with ClickFix attacks that bypass macro restrictions by tricking users into running malicious commands directly
  • 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://mayersoffice.com/userfiles/file/46292150513.pdf In PDF document text
    • http://geometrarontani.it/userfiles/files/reritel.pdfIn PDF document text
    • http://abimobiliare.pl/pliki/File/10197963999.pdfIn PDF document text
    • http://king-tableware.com/uploads/files/202109162009229002.pdfIn PDF document text
    • http://mail.teleserviciomalaga.com/ckfinder/userfiles/files/duzexorilipim.pdfIn PDF document text
    • http://kco.su/userfiles/file/borapoja.pdfIn PDF document text
    • https://corumosmanlimakina.com/js/ckfinder/userfiles/files/7475506080.pdfIn PDF document text
    • http://irvinenott.co.uk/ckfinder/userfiles/files/49094719135.pdfIn PDF document text
    • http://intemhathanh.com/img_duhoc/files/fozaveliwom.pdfIn PDF document text
    • http://hiroshima-teishaku.com/userfiles/file/72395361034.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9df1b6a05---noxuzivexoz.pdfIn PDF document text
    • http://slmj8.com/data/userfiles/files/66052466011.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16133dbad53d17---girilomawatozijujino.pdfIn PDF document text
    • http://benly-carson.com/product/files/dinafukitugevex.pdfIn PDF document text
    • https://parc-hotel.info/file/gimekomalonuw.pdfIn PDF document text
    • http://weiddy.com/uploads/files/202109042037555381.pdfIn PDF document text
    • http://salwex.hu/file/32591349660.pdfIn PDF document text
    • https://vitanov.rs/files/sokowafunotokolegulijek.pdfIn PDF document text
    • http://www.dreamstoreonline.es/ckfinder/userfiles/files/71549156860.pdfIn PDF document text
    • http://impressivetravelvietnam.com/upload/files/16023259268.pdfIn PDF document text
    • https://sthouseluxury.com/upload/files/89344643095.pdfIn PDF document text
    • http://gpe-el.pro/ckfinder/userfiles/files/gusudituwuvujanemikanesu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=how+to+get+the+moving+lock+screenPDF 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_off0000d8d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8D9 17920 bytes
SHA-256: 6de8671a244990aa9c56689deccdacbe7cd575e47aad0394cc7a3521e286141b
font_01_sfnt_off000106ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F06 10752 bytes
SHA-256: ce9dd0df1f46293834ce98164b3b8531355f8c13f0656e2f985957863269c630