Malicious PDF — malware analysis report

Static analysis result for SHA-256 b311a9046309eff3…

MALICIOUS

PDF

70.6 KB Created: 2021-09-26 21:12:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: aa9aa425774667deb359464678d4beac SHA-1: 412fcdc8635bb653f4a2c8ea317dc57a70d264c7 SHA-256: b311a9046309eff323cef77eabc5acb21cdeafe3dca0bbdb82203e9bf8b29cb3
134 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous external URIs, many of which point to disposable hosting and are part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is the primary mechanism for executing malicious actions within the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://valkexclusief.reviewz.eu/app/webroot/files/userfiles/files/45018076371.pdf In PDF document text
    • http://enjoy.sk/editor_uploads/system/files/zuxedazopede.pdfIn PDF document text
    • http://gk-eventus.ru/admin/ckfinder/userfiles/files/63958164486.pdfIn PDF document text
    • http://consol.hu/images/uploadedimages/file/43156497592.pdfIn PDF document text
    • http://kangmeideyiliao.com/uploadfile/file///2021092022521522.pdfIn PDF document text
    • https://soyana.de/js/ckfinder/userfiles/files/33012082794.pdfIn PDF document text
    • https://combrooncom.com/contents/files/73847941357.pdfIn PDF document text
    • http://www.biosafety.biz/ckfinder/userfiles/files/4981876512.pdfIn PDF document text
    • http://geose.ru/userfiles/file/bubixisetijopebaseralor.pdfIn PDF document text
    • http://castel.lu/userfiles/files/48796385889.pdfIn PDF document text
    • https://itandem.net/ckfinder/userfiles/files/tabimime.pdfIn PDF document text
    • http://ilsogno-bomboniere.com/userfiles/files/37349736022.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/temoxakosinakususajunig.pdfIn PDF document text
    • https://elesud.it/img_pagine/file/mowawetavone.pdfIn PDF document text
    • https://wtmasonry.com/ckfinder/userfiles/files/31288024996.pdfIn PDF document text
    • https://asi-filter.pl/files/file/pawopafekufisuzegafopibu.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613fadf4d6242---3567456180.pdfIn PDF document text
    • https://dyaa.club/uploads/file/jadoxag.pdfIn PDF document text
    • https://meesens.be/KrMee/Tekstverwerker/34502494288.pdfIn PDF document text
    • http://naszymsladem.pl/upload/file/68886879751.pdfIn PDF document text
    • http://a1-automotivegroup.com/upload/files/jopedazopabavurutatajo.pdfIn PDF document text
    • http://thelifelesson.net/home/tappingchanges/public_html/dowalumniusa/ckfinder/userfiles/files/weguzogemeberom.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614f2b3d10180---62492416131.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+see+connected+wifi+password+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_off0000b25c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB25C 16720 bytes
SHA-256: 7327eef4aedaefab45b767db3dd58d65eb60c810e27727779a7f6607ea53f0e1
font_01_sfnt_off0000dbd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBD9 10644 bytes
SHA-256: 0f8302295e595b4f057e044ad564ef115ba11ca51c3552a48cf6f72aa67716e7
font_02_sfnt_off0000f462.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF462 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1