Malicious PDF — malware analysis report

Static analysis result for SHA-256 8736a4f38ca43572…

MALICIOUS

PDF

76.7 KB Created: 2021-09-09 09:45:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: e0866b1276cd5654da483ed69a07fb5d SHA-1: 05581855619ef6ad78f307f469c2229e21dc660d SHA-256: 8736a4f38ca43572f273fbe87a19a48fd06adfe7abdab321dfbd32936d8d35c5
164 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript, which is a common technique for exploiting vulnerabilities or redirecting users. Heuristics indicate the PDF contains a link farm pointing to compromised WordPress upload storage and disposable hosting, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely involving exploitation for client execution.

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 http://www.oneworldkarate.com/fckeditorimages/userfiles/file/vizopunikapul.pdf In PDF document text
    • https://kocgrafikavukatwebsitesi.demowebsiteleri.com/upload/files/31735083729.pdfIn PDF document text
    • http://eastindiaspray.com/suvra/eastindia_spray/files/31751416579.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/4d62dabef4e376bfe21a3c4c34731371/vukigopovujerubiwim.pdfIn PDF document text
    • http://nachhilfeschule.havonix.com/ckfinder/userfiles/files/turatulukukewivefosax.pdfIn PDF document text
    • http://gimhaejazz.com/fckeditor/userfiles/image/40943043435.pdfIn PDF document text
    • https://grandhotelbulgaria.com/userfiles/file/23141227260.pdfIn PDF document text
    • http://kasand.com/userfiles/lipanagupadiw.pdfIn PDF document text
    • http://les-dvorik.ru/userfiles/file/ramenovirevuvojut.pdfIn PDF document text
    • https://elnativocoffee.com/silver/upload/files/78906575347.pdfIn PDF document text
    • http://i-dron.cz/data/file/24519164632.pdfIn PDF document text
    • http://www.prunay-en-yvelines.fr/ckfinder/userfiles/files/5501315943.pdfIn PDF document text
    • https://lotusmarinevn.com/upload/files/43075961086.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133c72aec000---69151274787.pdfIn PDF document text
    • https://apaman.ti-am.jp/js/ckfinder/userfiles/files/bunaputusizelixutukeso.pdfIn PDF document text
    • http://mtreurope.com/ckfinder/userfiles/files/zenijosezigowitagigi.pdfIn PDF document text
    • https://aslplastic.com/ckfinder/userfiles/files/25020364402.pdfIn PDF document text
    • http://ambiance-cinema.fr/wp-content/plugins/super-forms/uploads/php/files/e08b4abb0551f59541df7ab506d83e01/potiwelisezegumuf.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613495ce4a99e---mujujivurekewiferoguka.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/4b63580fc6f426db4a412c3e35ff249d/ninuna.pdfIn PDF document text
    • https://cuacuonbentre.com/upload/files/21716469824.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/5863f8d375b2dde99de7d1067eb3b1e9/29426999526.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=how+do+you+forward+a+text+message+on+androidPDF 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_off0000c633.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC633 11044 bytes
SHA-256: 3638934d716244d1a0ba887ec2b7567987c0ec518889c60f7e0f8cdd8524eb77
font_01_sfnt_off0000dfc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFC1 17400 bytes
SHA-256: a61aaf10d59929953bdf67d06e6062de653d081067462714dd2900bf261e8342
font_02_sfnt_off00010cf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CF7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1