Malicious PDF — malware analysis report

Static analysis result for SHA-256 f0cbd3190a581788…

MALICIOUS

PDF

74.2 KB Created: 2021-09-18 08:54:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6e1bcfda6e3d1cb0748a4b66820b7273 SHA-1: 7151546739507e98714cdd18f928719a28b7ac22 SHA-256: f0cbd3190a5817887978f3fc6d7f8e1646d782e40632771a3f63578b5e1d8ec6
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting, likely to obscure the final destination. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://thementalhealthadvocates.org/files/userfiles/file/lanenewobugogipapas.pdf In PDF document text
    • https://fullprotec.com/ckfinder/userfiles/files/mitonoxuzited.pdfIn PDF document text
    • https://0924055971.com/uploads/files/202109021548416508.pdfIn PDF document text
    • https://jurad.eu/files/file/pazebomodarinob.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/d42cf711b8096912429e1a0f2b73f3f4/97707103177.pdfIn PDF document text
    • http://elisa5888.com/shopadmin/upload/files/70278690593.pdfIn PDF document text
    • http://kiajihlava.cz/UserFiles/File/ponebip.pdfIn PDF document text
    • https://rajakedua.com/contents/files/milufuvedikibovudib.pdfIn PDF document text
    • http://www.mustwalge.ee/data/content/files/62711911887.pdfIn PDF document text
    • http://daimarconstrucciones.com/images/admin/file/debepabemewuvabal.pdfIn PDF document text
    • https://minhgianggroup.vn/upload/files/dipamaxagiledobiri.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/medaxukat.pdfIn PDF document text
    • http://contextuae.com/resimler/files/53509366557.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/77c3992d2e90c59b3e50a9d33fcd7844/duvaga.pdfIn PDF document text
    • http://silver.jo/ckfinder/blanc/files/jukexitexikibafajopa.pdfIn PDF document text
    • http://printrun.nl/userfiles/files/33798769194.pdfIn PDF document text
    • http://kingsfinancialconsulting.com/userfiles/file/radamuvekelijijijaxotaba.pdfIn PDF document text
    • http://www.farmaciabergua.com/userfiles/files/jikosidijurijavaju.pdfIn PDF document text
    • https://menokatea.com/ckfinder/userfiles/files/makinevowamomimapojefe.pdfIn PDF document text
    • http://101-games.ru/images/uploads/files/12610816175.pdfIn PDF document text
    • http://dd-eng.com/files/files/59247552151.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/k1k7co09o15e6f855ng3dihdmf/xokuxatofi.pdfIn PDF document text
    • http://hdg-gmuend.de/userfiles/files/58445941388.pdfIn PDF document text
    • http://lorofilmes.com/Uploads/ckfinder/userfiles/files/serikodopojuverapatun.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=minecraft+pe+for+android+apkPDF 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_off0000c1dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1DC 10484 bytes
SHA-256: 736fa15827bf3d867fc7c8f34dd88373d8c97ce7e96bf1dd9e856ab6ed46de43
font_01_sfnt_off0000d9cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9CD 16092 bytes
SHA-256: cd666c9cc11a48b188e8d6279235074e1e6abd751cd568b67c3f995faf02beee
font_02_sfnt_off00010300.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10300 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1