Malicious PDF — malware analysis report

Static analysis result for SHA-256 33af16d2fcdb8d17…

MALICIOUS

PDF

91.0 KB Created: 2021-06-20 10:57:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: cb3e62269ddf721cb974c5d406ac2d6b SHA-1: 35cc55faa13759e7ebf0cb3559a19d811c645151 SHA-256: 33af16d2fcdb8d172b46d29e9b47a4e787f373beeadda284f47928dc25fb4d0b
164 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised CMS platforms, suggesting a phishing or malware distribution attempt. The heuristic 'SE_INVOICE_LURE' indicates the document's content is designed to deceive users into clicking these links, likely to download a second-stage payload. The ML classifier and ClamAV detection strongly support its malicious nature.

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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/17059a983d4f636982002a832b1c8b87/48444664106.pdf In PDF document text
    • http://vidol.nl/userfiles/file/xejumajuvibumetodisit.pdfIn PDF document text
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/16a315185fad366cb0c223076cfd2735/75973556442.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf88c128604---76529720112.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/8d305f1997b8341756a38d12e8d27743/8117826366.pdfIn PDF document text
    • http://ipmarketing.net/userfiles/file/87783459921.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca571acf04---kuwilozafizetepenikanul.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/6d12dd3cb2776b6ed44a1270217746e5/lixulapijeronenevobukodup.pdfIn PDF document text
    • http://mysistermyfriendministries.org/clients/85776/File/movemisovubudutivolitato.pdfIn PDF document text
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/430ca53362c5b7fa05cfbf9813fd8c38/76907252648.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c79b021f1cf---95203403933.pdfIn PDF document text
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/7ec63b2d7afc26b29b1c30b5ebb6c51f/nitizuzebexedipenasif.pdfIn PDF document text
    • http://midel.me/userfiles/file/67120413478.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16092e9bb68874---2364982937.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/05e587db479135e5c2441a1124b066e4/mokovexexot.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/A3Ryygt5BCM/uplcv?utm_term=motor+vehicle+act+recent+amendmentPDF 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_off0001280a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1280A 5068 bytes
SHA-256: 98302d2c16f205ff3c78f36768ba508ba944714015406083d1a6af4b0ba2ba4b
font_01_sfnt_off0001392c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1392C 11188 bytes
SHA-256: c4e033b56b94f612c6b7aaf4dee03b6414c878b8b2c5a4b01ede8d531361dd2d