Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3b3f19806a439c4…

MALICIOUS

PDF

83.5 KB Created: 2021-10-04 21:51:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 4cdac564bd1f726527845b38e8bb2500 SHA-1: 3d7f0f19577268e383a39509488b44fac85e5d83 SHA-256: c3b3f19806a439c4057f4e4c2ac957fd0c224cbf8b2fa5afd0cabbe18424547f
166 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The 'SE_BROWSER_INSTALL_LURE' heuristic strongly suggests a social engineering tactic to trick the user into installing malicious software or revealing credentials. While no scripts were directly extracted, the PDF structure and embedded URLs point towards a phishing or malware delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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.
  • 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://liantoong.com/archive/upload/files/63022415495.pdf In PDF document text
    • http://giga.sk/storage/file/70954903909.pdfIn PDF document text
    • https://serpavenger.com/ckfinder/userfiles/files/88040671513.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/mesajolugojojepugep.pdfIn PDF document text
    • http://stagelight.pl/userfiles/files/70830671553.pdfIn PDF document text
    • http://kimura-shihoshoshi.com/userfiles/file/sejafero.pdfIn PDF document text
    • http://positiveforce.in/uploads/files/tajinagomitudemo.pdfIn PDF document text
    • http://arcdesantmarti.com/biocop/Images/images-editor/file/sujijazojajokodod.pdfIn PDF document text
    • https://hrmconsulting.biz/upload/files/92940060543.pdfIn PDF document text
    • http://bibliotekaszamocin.pl/img/upload/files/68730853214.pdfIn PDF document text
    • https://tvmreza.tv/ckfinder/userfiles/files/70548101660.pdfIn PDF document text
    • https://cecprint.com/images/file/62562724499.pdfIn PDF document text
    • http://gmtshipping.com/attachment/file/11642686530.pdfIn PDF document text
    • https://doublehair.center/upload/ckfinder/files/wuropunizukibukabekokavew.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/lidulamegaj.pdfIn PDF document text
    • http://joyandwowbook.com/upload/file/97277899495.pdfIn PDF document text
    • http://anapro.com/ckfinder/userfiles/files/gekura.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161535f31cd92b---radefasufetezelivege.pdfIn PDF document text
    • https://zaindu.drogomedia.com/files/galeria/files/35264889315.pdfIn PDF document text
    • https://alstar.uz/images/shared/file/puniwanikeniwomu.pdfIn PDF document text
    • https://laplacedesstores.com/upload/file/31871715419.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/e5e1d4b73ae6c373942032024c955106/nugaluwamupinovigep.pdfIn PDF document text
    • https://5974293.pasarantogel.com/contents/files/88818574035.pdfIn PDF document text
    • http://sriagasthiyarastro.com/FCKeditor/userfiles/file/50539304191.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=interview+questions+and+answers+for+celebritiesPDF 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_off0000dddf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDDF 10960 bytes
SHA-256: 1464f39f039f22be5c5ee3cdad05a8ac4f480e4242a85dd7189854df984c3b33
font_01_sfnt_off0000f74d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF74D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F5F 18512 bytes
SHA-256: 21ffb9d6fa24524d3b20796b1293103bc25ed1de4823769b163bd90ca9df05b9