Malicious PDF — malware analysis report

Static analysis result for SHA-256 f91fd1c0bf800f75…

MALICIOUS

PDF

88.8 KB Created: 2021-09-06 21:15:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ab24d0c149149a5e11e0f24a603d8065 SHA-1: 2a93a41633b993e8a85d7280723413057df3e467 SHA-256: f91fd1c0bf800f75b62d2eaec17c444da7da2a6f4562b9f49c4090fb9645f42e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the PDF structure itself is used to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://laborke.ru/uplcv?utm_term=cloud+architecture+diagram+pdf PDF link annotation
    • http://studiodrago.eu/userfiles/files/jewelaje.pdfIn PDF document text
    • http://jhsclassof63.com/clients/c/c8/c8cc7cee7579ddcd469b669c0eb172d8/File/13918503680.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b77aa6e3dd---14814794689.pdfIn PDF document text
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/50483957920.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/50273852750.pdfIn PDF document text
    • https://rittenhousesmiles.com/wp-content/plugins/super-forms/uploads/php/files/c55059a39986cee603c41fada48951f8/57575607107.pdfIn PDF document text
    • https://printsolutions.ro/uploads/wysiwyg/files/jexivinamewasujakavo.pdfIn PDF document text
    • http://mtlebanon62.com/clients/5/5e/5ee551a8be14a26d7d76bc5e90dd1372/File/tadabejunaze.pdfIn PDF document text
    • https://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/3c0c921500f41e5f11fd655e9235ca9d/rozifoxifelewovulure.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ed3010cf5b5---87372828272.pdfIn PDF document text
    • http://drivescuolaguida.it/userfiles/files/lexedobezijixixarumajel.pdfIn PDF document text
    • https://hagakure.by/upload/editor/files/kudopodokitog.pdfIn PDF document text
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/f2e147b1aa9f727c628f7585c254052e/nuvijurada.pdfIn PDF document text
    • http://veterina-hrib.cz/user-uploads/files/77655081394.pdfIn PDF document text
    • https://eyetracking.pl/userfiles/file/80177364651.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/2a307431a812d88528818d30e55ccebb/90033517354.pdfIn PDF document text
    • http://archi1919.com/smlclub-files/file/jiwize.pdfIn PDF document text
    • http://jp-photo.cz/soubory/files/kupatogefifefuwopoxuxi.pdfIn PDF document text
    • https://bjjewels.net/nbloom/fckuploads/file/tebefebetevigasip.pdfIn PDF document text
    • https://limsurdua.com/contents//files/zatadunefetuziwolagiru.pdfIn PDF document text
    • http://mustang.tom.ru/jsplugins/ckfinder/userfiles/files/2732498389.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_off0000f35f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF35F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B71 18584 bytes
SHA-256: b388030540387edd996c7bd6ffe366c0752c680a35262de73e044b3b66945959
font_02_sfnt_off00013c96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C96 10928 bytes
SHA-256: f1efc4b63b83b7401dffff28cd40186cb5d3a1c1276d5e3474ec95972ddf5b35