Malicious PDF — malware analysis report

Static analysis result for SHA-256 5396743ec472c3db…

MALICIOUS

PDF

71.4 KB Created: 2021-09-14 09:20:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 671d85e99d2ec90689e30c9e2692d49c SHA-1: 38baeda1d0dde60235f49c560b84751f7a9d315c SHA-256: 5396743ec472c3db2788696ca2bf35a5a037d9106a7d86aa66d3b4fa79ca2165
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF document containing embedded JavaScript and a large number of external URIs, many of which point to disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common technique for exploiting PDF vulnerabilities or redirecting users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

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://coretry.ru/uplcv?utm_term=android+camera+x PDF link annotation
    • https://skyzoan.com/cake/beta/userfiles/file/93365145772.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/fepimubaza.pdfIn PDF document text
    • http://bn-biz.com/userData/board/file/90487413595.pdfIn PDF document text
    • https://asiahealthcaredentalcentre.com/ckfinder/userfiles/files/9581080217.pdfIn PDF document text
    • http://www.naturhalles.fr/fckeditor/userfiles/file/newapivanetokumos.pdfIn PDF document text
    • http://bjsixiang.com/jingkelun/userfiles/files/20210913140720.pdfIn PDF document text
    • http://hichipper.com/hichipper/uploadfile/file/2021090509015473499.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/zelotitafapubaron.pdfIn PDF document text
    • http://expertworker.paraleumarian.ro/app/webroot/files/userfiles/files/biviwadikutejofigogep.pdfIn PDF document text
    • https://gsm.company/ckfinder/userfiles/files/jumikanamadatuvalodador.pdfIn PDF document text
    • https://leonardscopysystems.com/home/leonards/public_html/ckfinder/userfiles/files/nisozel.pdfIn PDF document text
    • https://jv-cms.crazy-jessie.nl/uploads/files/bitaparawitos.pdfIn PDF document text
    • https://prcomponents.com/ckfinder/userfiles/files/wafuwif.pdfIn PDF document text
    • https://globalybm.com/ckfinder/userfiles/files/1630907729.pdfIn PDF document text
    • http://etasystem.net/userfiles/files/96063394344.pdfIn PDF document text
    • http://saddabro.com/userfiles/file/viputunovezud.pdfIn PDF document text
    • http://simonkuehner.de/gfx/userfiles/files/nimaxixajagivuravoxubut.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/9e4ce9717dcd12a9a3c5063068e06bb7/9291677400.pdfIn PDF document text
    • http://grabnerestriche.at/33102258694.pdfIn PDF document text
    • http://jsdarvin.com/files/texagemufutebevotike.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613509c517c6b---92031442070.pdfIn PDF document text
    • http://lexen.ca/userfiles/files/meguwefifaf.pdfIn PDF document text
    • http://www.vljainandco.com/userfiles/files/20108562422.pdfIn PDF document text
    • https://clubberia.com/js/ckfinder/userfiles/files/93441238547.pdfIn PDF document text
    • http://tprcindia.com/ckeditor/ckfinder/userfiles/files/pakokorowo.pdfIn PDF document text
    • http://dxline.eu/userfiles/file/dejujigubaxo.pdfIn PDF document text
    • http://perechen-izdaniy.ru/js/ckfinder/userfiles/files/52876903558.pdfIn PDF document text
    • http://franzoesischebulldoggen.eu/userfiles/file/gomuguko.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_off0000b952.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB952 15612 bytes
SHA-256: 5b99803c43daaf7a878bd866600c39b8b52d7f56abdaaa9604fd3176dd7e0406
font_01_sfnt_off0000e0ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0EC 10300 bytes
SHA-256: bfa25f5daf8f32bc07b0a91f1b8f0da11e985c300e9e8eaad65779780d610499
font_02_sfnt_off0000f818.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF818 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1