Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef35033641ae4832…

MALICIOUS

PDF

75.5 KB Created: 2021-06-14 09:30:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 0fb8c9c022ac69bf7188dffce29098b9 SHA-1: 31158a403d207cc07948a222cbf3008946ea70e0 SHA-256: ef35033641ae48321039f02a518b579450bf62152f7c162df84d41ef59e2bcfd
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The file is identified as malicious by ML classifiers and ClamAV, and exhibits characteristics of a social-engineering lure to install browser extensions or updates. It contains numerous links to external websites, many hosted on compromised WordPress sites, suggesting a phishing or credential harvesting attempt. Although no scripts were explicitly extracted, the PDF structure and embedded URLs indicate a malicious intent to redirect users to potentially harmful content or downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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
  • 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://coretry.ru/uplcv?utm_term=crazy+romance+full+movie+online+english+subtitles PDF link annotation
    • https://luxmarketing.agency/wp-content/plugins/super-forms/uploads/php/files/mgak3jkug51ul7bau2kb8976cm/kivamipokov.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160837b10009cb---82407574153.pdfIn PDF document text
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a168c665f94---wileregizipotopabofova.pdfIn PDF document text
    • https://ckmusicdesign.nl/userfiles/file/51366178500.pdfIn PDF document text
    • https://plasy.com/uploads/file/50347001514.pdfIn PDF document text
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b79a4c09f84---jurunibavukibolu.pdfIn PDF document text
    • http://humanitool.ru/userfiles/file/20702362690.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/18565665425.pdfIn PDF document text
    • https://agrimal.pl/userfiles/file/69168913647.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/9bf1d666b216463f29b0431660e679f8/71270103738.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c421e7c3022---95859444211.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/3369681211.pdfIn PDF document text
    • http://gagutp.com/sa_upload/userfiles/file/20210606161618.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609ab42b971e4---73844717397.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA89 5552 bytes
SHA-256: 18051afdbf71e19ae1d571d1000220495ba0d6bf6483f0834c0668779269f8a8
font_01_sfnt_off0000fd5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD5C 10444 bytes
SHA-256: 648ffbff7c63093dc54ba82cf4cddca5259152119ac9dc19598918405ccb7f99