Malicious PDF — malware analysis report

Static analysis result for SHA-256 54f1e1c2135482d7…

MALICIOUS

PDF

77.9 KB Created: 2021-06-13 10:43:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: f2b95b2a68f88c657a8221955c6aa46c SHA-1: c1bdab673d76fdd677f2ecec2d2851cc03b311ae SHA-256: 54f1e1c2135482d7da32524d797b89069520ea0ed9d9db686594aba956319592
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm or phishing campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • 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=defensive+driving+course+final+exam+answers PDF link annotation
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/faa81f453faef217b7d83389a65674cc/piwoxu.pdfIn PDF document text
    • https://airbays.com/userfiles/file/25832182765.pdfIn PDF document text
    • http://0vote.com/ckfinder/files/vabizalid.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b5f6b0b68b---52171350345.pdfIn PDF document text
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/f86a1d2fc96a9c0811f7f77d769abec0/9046152716.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/731d5844f7c929036a0352d4b712284b/93033120161.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/t5gjuk5ql0imjmju6lgan6naf6/jawad.pdfIn PDF document text
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/16083b0063468d---69041192549.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/vofemilubodobiximosisi.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608db0962fc94---11112818840.pdfIn PDF document text
    • http://redwoodpwr.com/wp-content/plugins/super-forms/uploads/php/files/o39pvjlscsknbma2dkvvvmiom5/kotudodejibuwat.pdfIn PDF document text
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073ee970f8d4---25286118440.pdfIn PDF document text
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/6ua35r9mv45agtsmaeqb7rnq6p/37843513954.pdfIn PDF document text
    • https://dubigroup.com/admin/fckeditor/editor/filemanager/connectors/upload/file/vuxifiwetizesavi.pdfIn PDF document text
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/25gc0ke1u87nnp7mpa2klqk9a6/21169427806.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_off0000efe7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFE7 5560 bytes
SHA-256: a439b1c0268b9c003d65942449d9c04ce544fc0521014d3ccf2a3975c6b9561b
font_01_sfnt_off000102da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102DA 11616 bytes
SHA-256: d084ba8830be309bba8bf322e294e51af53f1f4607115f240e7acab0a2340367