Malicious PDF — malware analysis report

Static analysis result for SHA-256 36d092492f88621d…

MALICIOUS

PDF

82.0 KB Created: 2021-09-16 08:17:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ede99c3226b2a2697fe18048e633ca1c SHA-1: e6eebc87e441d771bad7ff007673ad13b56b1838 SHA-256: 36d092492f88621d0cca914f506436e70461ebab56ffc47fe25cad0229058bf8
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting a phishing or SEO manipulation scheme. The embedded URLs, while some are marked benign, contribute to the overall pattern of directing users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/41982afe07effec69568e8162d01411b/63481566467.pdf In PDF document text
    • https://eco-translation.ca/upload/editor/file/difabalupinonosij.pdfIn PDF document text
    • http://tahyuh.com/uploads/files/202109082218163360.pdfIn PDF document text
    • http://yangs-ns.com/ckfinder/userfiles/files/20210911231735.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/fadoluzalexu.pdfIn PDF document text
    • http://sushibelovo.ru/files/bepafedux.pdfIn PDF document text
    • http://ozdesignhouse.com/app/webroot/uploads/files/kusudamukod.pdfIn PDF document text
    • http://ergo-logo-bamberg.de/userfiles/file/17083640722.pdfIn PDF document text
    • https://starfoil-mail.nl/uploads/wysiwyg/37655230030.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1613e4d6205801---81845603549.pdfIn PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/398cd2cb6cbd93208602ca2af3365aa6/25772963455.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b53b44bfe2---kikaremotojudopum.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/63ca852f13e14d3d411e00a968392d59/46616958827.pdfIn PDF document text
    • https://phatgiaolongan.com/upload/ckupload/files/taratog.pdfIn PDF document text
    • http://thenikharvconsultancy.com/userfiles/file/8192112471.pdfIn PDF document text
    • http://www.logistiekverbeteren.nl/ckfinder/userfiles/files/31913559265.pdfIn PDF document text
    • http://fuyu.010bi.com/ckfinder/userfiles/files/vasizevizafiselazosasigu.pdfIn PDF document text
    • https://pyccenter.com/images/Upload/file/tababudugajododibesu.pdfIn PDF document text
    • http://daindnc.com/fckeditor/userfiles/file/rarebutegenodiloz.pdfIn PDF document text
    • https://renesens21.com/ressources/upload/files/wixugujexawuw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=clash+royale+online+hackPDF 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_off0000dc76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC76 10464 bytes
SHA-256: 31025539e700299479d01c0fcdbb98ca14d93f771eac696211a4b050c532a5b1
font_01_sfnt_off0000f42c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF42C 18016 bytes
SHA-256: 27809803f2a86646c72ada417cc88554613fb3b4e42a580aa31664a98e57cc33
font_02_sfnt_off000122ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122FF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1