Malicious PDF — malware analysis report

Static analysis result for SHA-256 397a539b0be3a7a7…

MALICIOUS

PDF

66.1 KB Created: 2021-05-18 10:10:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: e8216a8b3b03649c97a3554bd55015d0 SHA-1: 1643bec7d07bd1dca82cdc55a5b0d66bdf7cefa0 SHA-256: 397a539b0be3a7a737abaca15581dc93b2233a73dc7f729ea3f6d32cb4293d52
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a link farm hosted on multiple compromised WordPress sites, directing users to download a "Padi rescue diver manual". This pattern is indicative of a phishing lure or a distribution point for further malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely involving the exploitation of PDF vulnerabilities or social engineering.

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://chcial.ru/uplcv?utm_term=padi+rescue+diver+manual+pdf+free+download PDF link annotation
    • http://planbmedia.hufiles/98429207626.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080afbc31f6a---61850860668.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/ukc2jj6q67hmlvh588j5l87af2/bikolasawemivipowagizixe.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/c837j3g7kgonsqdqt0mdifda20/gezukanomuwizuze.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/f1ba97de7bdf16280869adc5ac4de3fc/tameleva.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1609e113d6cd7b---furotisuzad.pdfIn PDF document text
    • http://projectbudapest.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160734ca7995e2---fapisizoxalusudirivuv.pdfIn PDF document text
    • https://botorka.ro/userfiles/file/xirikivetomojisivalorin.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/c11e0a30725bd596760a934701dbb7b9/vibavowobenisipexonamiji.pdfIn PDF document text
    • https://thejinglelab.com/wp-content/plugins/super-forms/uploads/php/files/5ke6rj2egojskb60lrg2287vs1/86307258181.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/afa3416b00b5105ee9aa52c3d565e368/90621018107.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609f898c8f8a1---labizuxab.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/af6980436080b4f6aa4d02bd32b5d32e/woduguxeze.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089340971960---nidapinafazu.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/160815fadb4830---deluloni.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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_off0000c5d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5D8 5452 bytes
SHA-256: f0ac4ae141a738a6a01a18de6bf4eee1c8ca0f90efd62aab124d559ceeb37ef2
font_01_sfnt_off0000d865.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD865 10192 bytes
SHA-256: 346b2f1acb3ed9619e00cfd49fe8dcaca4e0265c3a72c4fbe8ecf7ac59cfdc93