Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa8caa4779baab78…

MALICIOUS

PDF

73.9 KB Created: 2021-06-19 15:00:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: cb11f35d61117de5ce9b67c4d7d12e58 SHA-1: 0611cc00db806b42be5d6de7b81901de05c0eeb5 SHA-256: aa8caa4779baab782dbdb232be87a2a64feb2d6d83e5e1ecca845293431e7a7f
156 Risk Score

Malware Insights

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

The PDF file contains a link farm directing users to multiple external URLs, some hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded URLs and link farm structure suggest an attempt to lure users to malicious content.

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.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3edb536d7---75732883628.pdf In PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080fc3a35a1f---wexewijirejajupiguwepifad.pdfIn PDF document text
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/p3i4ve02h5m0skqnigj1pq7vgv/rinezevopujij.pdfIn PDF document text
    • http://bscsaoner.in/ckfinder/userfiles/files/dudanexumopojinunapex.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7156ea0jo7kj28qf8ioh1u8p60/kopegipikaje.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16077e180af02b---35503395095.pdfIn PDF document text
    • http://marymo.ru/uploads/files/33631642799.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c394c80b9e---18373589019.pdfIn PDF document text
    • https://soportedevida.mx/ckfinder/userfiles/files/lesabukipevibat.pdfIn PDF document text
    • http://tofuyatogo.com/uploads/files/35496827175.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16098e87739563---tazob.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16078fdff67ad2---28893898054.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608502f88e3db---75283023039.pdfIn PDF document text
    • http://joelcsimonesq.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/wijadofutila.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16081c18f1e29a---75273776404.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/14e6cd10cd0ab33f2dcae32bd76a33d7/31318458317.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/cv9VXjIrmdE/uplcv?utm_term=human+body+part+drawingPDF 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_off0000e247.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE247 5364 bytes
SHA-256: 976c5b9021265d7b7d4468dd4efdd24285e33c3c9e1aa626eeb0b4ae23eb1622
font_01_sfnt_off0000f47e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF47E 11252 bytes
SHA-256: f89d3269eea01384eb514636e2e9904edffe9b1161f225fd0f4ad4ab0158695d