Malicious PDF — malware analysis report

Static analysis result for SHA-256 42500d1900115737…

MALICIOUS

PDF

105.3 KB Created: 2021-05-28 13:15:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: b85a0efc5b64839e70b6098a2f9d99a1 SHA-1: 2331561a32cd99d2666890491cd444b37f9cf14d SHA-256: 42500d1900115737c0581198031f9d50f2768e5daa0518b5f695f1d182ef619c
164 Risk Score

Malware Insights

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

This PDF was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious content. It functions as a link farm, directing users to other PDF files hosted on compromised WordPress sites. The presence of numerous distinct hosts and the use of WordPress plugin upload directories suggest an attempt to obscure the true origin of the malicious content and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/0csbrbb62ercaomhbugnpnadr9/piloko.pdf In PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce6c536fd2---93602700811.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/64efj530n6f4059pt75vbucgr8/76468071894.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/97db7e041c05db77967f884d96ecd10d/59718585221.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/16081720eecb07---92844210297.pdfIn PDF document text
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/a3511b2315e6dfd18e2c0ffb3d8416af/81713965716.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160aae025e186c---ditolegenixomidakojonimuw.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/160807d8ad4591---5347864991.pdfIn PDF document text
    • http://www.sevenchurchestour.net/seven/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9b7891311---11060382079.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/64685008714.pdfIn PDF document text
    • http://domeinbeverdonk.be/assets/files/file/24965480738.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/7233b08212499575aa2ab9fb0abecb21/87577280827.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9fa30971a6---mapetapekowawuvixibug.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/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=who+is+percy+jackson+in+love+withPDF 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_off000161b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x161B2 5428 bytes
SHA-256: 637c739c0b5528bd32ecf9b6f6a7c6d82753779ad16112e5968cfc25e04b3105
font_01_sfnt_off00017447.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17447 10700 bytes
SHA-256: 4d11bc21f6bb90b2839d8d2f3f65211e52ec66cc42a916eef489852dba370a89