Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4f53b395d1dc90b…

MALICIOUS

PDF

87.9 KB Created: 2021-09-18 16:44:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 73081403f2985ef2c6c43a9f769ffac5 SHA-1: c52b41b4b9397c4b1d4661030a26ba80ebda0433 SHA-256: f4f53b395d1dc90b4931d970ece50c6865c1ac13d3ea877fae91171934f605fd
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to external URLs, as suggested by the PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics, which are often used in phishing or malware distribution schemes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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
  • 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://hoangnhataudio.vn/media/files/62069868187.pdf In PDF document text
    • https://soudurelausiere.ca/upload/editor/file/simuwutigumomonajani.pdfIn PDF document text
    • http://ymmicro.com/files/files/mebemomapakuramenajat.pdfIn PDF document text
    • https://wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/laloxolojud.pdfIn PDF document text
    • http://hoadon-dientu.net/images/files/28593848419.pdfIn PDF document text
    • http://cachnhietwin.com/luutru/files/soxoxavovenixezabesozuwi.pdfIn PDF document text
    • http://ambvetfanini.eu/userfiles/files/50861347395.pdfIn PDF document text
    • http://webinaris.eu/ckfinder/userfiles/publics/files/jexojokoga.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/xujasadenapevepajote.pdfIn PDF document text
    • http://acupunctuuryao.nl/ckfinder/userfiles/files/pidotesawadux.pdfIn PDF document text
    • http://tokyosushilohaus.com/uploads/files/sibovivuk.pdfIn PDF document text
    • https://www.iieng.org/editor/ckfinder/userfiles/files/64026317659.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/bmop5b16h2ihlddrpa4iek4430/27403165901.pdfIn PDF document text
    • http://hkacca.com/userfiles/vonelinem.pdfIn PDF document text
    • http://daisin1977.com/js/upload/files/zopakozatesizekerarot.pdfIn PDF document text
    • http://brainbond.ro/userfiles/file/rudireralarosajekotisi.pdfIn PDF document text
    • https://sanipacific.com/attachment/file/jinositosa.pdfIn PDF document text
    • http://revistaspontan.ro/assets/ckfinder/core/connector/php/uploads/files/39161454281.pdfIn PDF document text
    • http://taxiluzern.ch/khurasan/userfiles/files/puwinixepituvaxesiregi.pdfIn PDF document text
    • http://air-ned.com/uploads/files/xojipake.pdfIn PDF document text
    • http://tumakuruvoice.com/tumkurvoice/ckeditor/ckfinder/userfiles/files/45273720231.pdfIn PDF document text
    • https://shopexpert.com/app/webroot/files/userfiles/files/11036550856.pdfIn PDF document text
    • http://rungrawin-itt.com/userfiles/files/zugeludajodivefajo.pdfIn PDF document text
    • https://gancza-yacht.pl/userfiles/file/difiguf.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134276adc76b---vexigugepitupumusi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=the+best+moba+games+for+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_off0000f593.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF593 10856 bytes
SHA-256: 25bd9d8339345f0bb62faabf2a1845b4d5f3bf1365ca3f0c58c4de9f1dca7fd3
font_01_sfnt_off00010e3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E3F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012651.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12651 16924 bytes
SHA-256: eb619c460cfb448c5b10272521f9966ec88313c3713c80e5253b29904359cb97