Malicious PDF — malware analysis report

Static analysis result for SHA-256 9bb43e748a7db8fb…

MALICIOUS

PDF

76.7 KB Created: 2021-06-20 14:27:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 78c8661846231904110de145109f9d6a SHA-1: 58487a8b787cfb71ec530c9c458f71d858ff7753 SHA-256: 9bb43e748a7db8fb47fe41b28fd8c26b30e6a538279ceb008ff86a674d2e9b2b
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised CMS upload storage, suggesting a phishing or redirection scheme. The document body is heavily obfuscated and contains metadata indicating it was generated by wkhtmltopdf, a tool often used to create malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/0o7cgkn98q3drtvbmuvknjtfji/madazon.pdf In PDF document text
    • http://eko-inwest.eu/upload/file/50275892155.pdfIn PDF document text
    • http://agro-vostok.ru/userfiles/file/28960869366.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f1d9ebc5cf---geduraxakabibumanu.pdfIn PDF document text
    • http://abacusnancy.com/userfiles/file/nofagafufesiroxale.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/6od47q2hmlsrbeq6lvv22613mh/72231502897.pdfIn PDF document text
    • http://mtlebanon62.com/clients/5/5e/5ee551a8be14a26d7d76bc5e90dd1372/File/48342586253.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ada2065f4a1---bemotabit.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/a43c1e8149a81d8873bbb67925bde419/lazamadilunetibupuwigak.pdfIn PDF document text
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075b19001ae5---kepopalolovevo.pdfIn PDF document text
    • https://razdolle.by/wp-content/plugins/super-forms/uploads/php/files/4fim9lb32mv1kqcborr6k5bh04/lefefanodowovereron.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/r7khq768829doclgk1phg5qoq6/61859725946.pdfIn PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ffc6a4d7ad---vikexekamavufotenidaz.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=dragon+ball+z+girls+sexyPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF11 4920 bytes
SHA-256: 0a2c819b371e0cbdce01c6f8c8d5d16c11f1b6acc97710c508a115b8040a53a7
font_01_sfnt_off0000efdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFDB 11692 bytes
SHA-256: 224245baee6535601cee14f92faf966d18075c0948e35f7ee317d1773457341c
font_02_sfnt_off000117b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117B7 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361