Malicious PDF — malware analysis report

Static analysis result for SHA-256 50cf9cde8e8d5c10…

MALICIOUS

PDF

72.5 KB Created: 2021-09-06 02:51:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: fe2c55a3d59e63e5b185caff158264f4 SHA-1: d3fc25680b95763ce72d146d87e0c9f947ce86f5 SHA-256: 50cf9cde8e8d5c10e8d57c327291d376cf19c9084250be7bd605f8b4719407f9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://biothiennam.com/media/ftp/file/68469054078.pdf In PDF document text
    • https://xo-sound.ru/userfiles/file/70020019042.pdfIn PDF document text
    • https://nullemont.fr/nullemont/ckfinder/userfiles/files/gasofelozisagofarizil.pdfIn PDF document text
    • https://rubenoferro.com/userfiles/file/dovike.pdfIn PDF document text
    • http://asckhn.com/acskhn/userfiles/file/86992965681.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/2fc23c13dca78a7733cf3abff55982e9/43019938248.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/8f1dee4aed8fe5d86155e9b852847f68/42333517312.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d90deab1a3---selirodipefitegon.pdfIn PDF document text
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/sqk9burm4egj5o3oce9814n11f/dopan.pdfIn PDF document text
    • https://giustofiori.it/file/gamigovoxew.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/653b4dfd761d216347df36a9a9d90148/25513681334.pdfIn PDF document text
    • http://studiodebiaggi.eu/userfiles/files/worebixisiza.pdfIn PDF document text
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/16099de3d329f0---nozurububugiro.pdfIn PDF document text
    • https://ou-ravda.com/ckfinder/userfiles/files/19320256492.pdfIn PDF document text
    • https://uzunlarpeynir.com/dursun/upload/files/13500886962.pdfIn PDF document text
    • https://la-klamm.org/Files/files/98119902701.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/xuvusadefadivu.pdfIn PDF document text
    • https://pezenasenchantee.fr/userfiles/file/kakokupelaborupubituvi.pdfIn PDF document text
    • https://profipreklady.cz/www/ckfinder/userfiles/files/59110629362.pdfIn PDF document text
    • http://alnadaoil.com/userfiles/file/filipexuto.pdfIn PDF document text
    • https://aitalk.vn/upload/files/88501743296.pdfIn PDF document text
    • https://przyklejki.pl/userfiles/21816463296.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=panasonic+lumix+g9+user+manualPDF 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_off0000b767.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB767 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF7E 10844 bytes
SHA-256: f21a1296d68860a34648e37df50de03e03121b243d35caddc6c5586fd9e9868a
font_02_sfnt_off0000e88e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE88E 16572 bytes
SHA-256: 54336cb8aeca41b51631ccae9d74bb6c39152fd2e8579fc3b414f8e5130bcd02