Malicious PDF — malware analysis report

Static analysis result for SHA-256 68615c6a45fb92b4…

MALICIOUS

PDF

71.0 KB Created: 2021-06-25 01:38:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 45dd4d13519837f584dc54cea7732858 SHA-1: d24a688f082498f3816e2d54f08c184e23a749f0 SHA-256: 68615c6a45fb92b4ea5d6bf56b0f110fa7210c5b88b839e473195cbb7f5f540b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a link farm with numerous URLs pointing to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as a phishing trojan. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDF documents from web content, further supporting the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/160736d658a423---17406524037.pdf In PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d0e8d494ae---18263383886.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a4a117dae14---43327235944.pdfIn PDF document text
    • http://computergramm.com/userfiles/file/47612177193.pdfIn PDF document text
    • https://marmarases.com/upload/ckfinder/files/dolebobakefagug.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160971285be546---81726028425.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/m281bal5botn229700nkfb6u26/mibuzuvipatizoronugi.pdfIn PDF document text
    • https://deconkhoemanh.com/wp-content/plugins/super-forms/uploads/php/files/sfqa0qs13ul8rd0qoqpjujncij/15803736856.pdfIn PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/38342a8a75b058b9c0cff832d9b2bf4f/85762595413.pdfIn PDF document text
    • https://warsztatgdynia.pl/app/webroot/media/files/327222713.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7714a460ec---fimufisurulisuxanetaw.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/7228239708.pdfIn PDF document text
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/a77d3bf5ca892fba3ffd898aa677f494/dutowepibamodekepejejek.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/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=dormir+al+sol+bioy+casares+pdfPDF 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_off0000c643.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC643 5144 bytes
SHA-256: 9ede899d71103801c7542f294be4383e792276f6700cc9a63412636f5c6725be
font_01_sfnt_off0000d7b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7B9 12788 bytes
SHA-256: 27abf4a72b06c53b18f356b7b6318b48b4c65e0fe52390f2773b4fbd3188df3f
font_02_sfnt_off0000ffab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFAB 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f