Malicious PDF — malware analysis report

Static analysis result for SHA-256 1529897652b6dfe2…

MALICIOUS

PDF

72.9 KB Created: 2021-06-25 08:51:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 8f10cd74b80b91d8e8b52b6e95d4f363 SHA-1: 00aa0b8febeb0290c96b91c6ab30a0bfb35e72d7 SHA-256: 1529897652b6dfe29b4cd4381e2072881c98a093ecb2929be9cadd5311eafdfd
156 Risk Score

Malware Insights

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

The PDF contains numerous links to other PDFs hosted on compromised websites, suggesting a link farm designed to improve search engine rankings for malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The presence of multiple external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic point towards an attempt to distribute malicious files through deceptive search results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/4m4vtcshpq9g39abdv4ltg9fq2/verap.pdf In PDF document text
    • https://wpsqld.com.au/wp-content/plugins/super-forms/uploads/php/files/b0bedda4c109fde1db003b4bf1bda745/79078021195.pdfIn PDF document text
    • http://starrsgazette.com/admin/images/file/gefovorotafatoz.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609aad6f775d3---lamupajijewodipew.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160858ba9603c7---duzagezobezovivegarev.pdfIn PDF document text
    • http://dirabrealtors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607eb559e4f6d---jofimexaxuvu.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021061905553123.pdfIn PDF document text
    • http://4reality.cz/userfiles/files/dojuvefulaxezeloxalopa.pdfIn PDF document text
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160736ab546cd0---vurev.pdfIn PDF document text
    • https://glycocalyx.nl/userfiles/image/file/fumizuxudimobufowejonip.pdfIn PDF document text
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/1085fbeb9cef0c4d6f1863563164b03a/67121951668.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/rrls21v3p2s8ghmhhn0kc8og5n/83931406183.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160b085c1bb757---taxeniduvugade.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/160bdc701c4baf---18752600334.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16077f0d6c00c5---fobujatujuraxuvu.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/1608e9b168803a---riwupibivuk.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=half+girlfriend+book+free+pdf+downloadPDF 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF75 5288 bytes
SHA-256: 4507738edb477d8462118b0ceaa80d17f62f25e47edbdcb37fdf892d0215c70a
font_01_sfnt_off0000f18e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF18E 10916 bytes
SHA-256: c49b9a9274eb53ae9e492123cdb432880e524d5268b5e82dd4091412d1080814