Malicious PDF — malware analysis report

Static analysis result for SHA-256 87ed635d7d3d32b2…

MALICIOUS

PDF

74.0 KB Created: 2021-09-13 16:13:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: d9488952cf51fb7c076dd1cd766d1e7e SHA-1: 9bce2a3d82ce240513e9cc41279b78f70b7f8e17 SHA-256: 87ed635d7d3d32b2dc2bd85cd3831b907e76ca748e45b3b9f00beb4eb5ba6a8b
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code within documents. The numerous external links, many pointing to disposable domains and using UTM parameters, suggest a phishing or malware distribution campaign. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to trick users into downloading further payloads under the guise of a firmware update.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://infrive.ru/uplcv?utm_term=android+tv+firmware+update PDF link annotation
    • https://estduquebec.com/scripts/php/xenocode/lib/ckfinder/userfiles/files/lusakisazoxurarasine.pdfIn PDF document text
    • https://www.santaterezinha.com.br/js/ckfinder/userfiles/files/wopegajutatomupufonakum.pdfIn PDF document text
    • http://asia-test.informacittadino.net/media/files/46908797041.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/74733960726.pdfIn PDF document text
    • https://vayamcs.com/content_files/files/7230656708.pdfIn PDF document text
    • http://samurairamenbar.com/uploads/files/jebujibexemo.pdfIn PDF document text
    • http://superfasttv.com/uploads/files/xixozoro.pdfIn PDF document text
    • http://dxline.eu/userfiles/file/13066318422.pdfIn PDF document text
    • http://xn--12cmi2byac9cdhd0hra6d7bxkwbgj1gch.com/user_img/files/78186130452.pdfIn PDF document text
    • https://navoloki.mebel18.com/uploads/files/sesuvugogif.pdfIn PDF document text
    • https://maydangson.com/vietkiendo/upload/file/rujinuzabilixa.pdfIn PDF document text
    • http://www.farmaciapenil.es/userfiles/files/lazerasireronidifekevoxut.pdfIn PDF document text
    • http://chapelguild.com/images/usr/xedivubi.pdfIn PDF document text
    • http://thrifty-uy.com/files/others/40506068251.pdfIn PDF document text
    • http://kayamedbursa.com/userfiles/file/64694963854.pdfIn PDF document text
    • http://belniig.by/public/file/xagimejepejonenaxifikixor.pdfIn PDF document text
    • http://aviatechinform.ru/sadm_files/fepaginanuw.pdfIn PDF document text
    • http://litroshaber.net/resimler/files/volivarani.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///79529072049.pdfIn PDF document text
    • https://postele-z-masivu.sk/ckfinder/userfiles/files/88078457419.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/161352601613fa---83363331679.pdfIn PDF document text
    • http://jawarakreasi.com/file/wipemaneboporobinerabob.pdfIn PDF document text
    • http://vinhhangvien.com/upload/files/92499456633.pdfIn PDF document text
    • https://mallarpurnaisuva.org/go/file/23073213105.pdfIn PDF document text
    • http://devitohomesorlando.com/userfiles/files/fukufiwosixer.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_off0000bf1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF1B 10676 bytes
SHA-256: 718e9f6344df8be5949263d3290f2df13f0e19a41c88e45e281726d98a0444bd
font_01_sfnt_off0000d7a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000efb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFB3 16768 bytes
SHA-256: 9049027056e222ef91dd7c22ae44c8f975f3d2c991c81119f2df0879effe9d39