Malicious PDF — malware analysis report

Static analysis result for SHA-256 7f0fb8f4498c8d01…

MALICIOUS

PDF

69.2 KB Created: 2021-05-27 17:59:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: fcf88b1cf5f60cfc92586aa2defea6c6 SHA-1: 2816120cb5ba7c56a0da9061df03c4091f2e6f01 SHA-256: 7f0fb8f4498c8d0111cf4538776a2afaf4a5051cd95b07ae222586cbf6e43834
156 Risk Score

Malware Insights

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

The sample is a PDF document that contains numerous links to external websites, many of which are hosted on compromised CMS platforms. The document body, though heavily obfuscated, suggests a lure related to an excuse letter. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics, along with a high ML score and ClamAV detection, indicates a malicious intent to redirect users to potentially harmful content or download further payloads.

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://synerhu.ru/uplcv?utm_term=sample+excuse+letter+for+being+absent+due+to+dysmenorrhea PDF link annotation
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/b1700df7bb800a17898b2b50d4bbeaa4/90750874342.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080d834d216d---vuluravepegom.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16098b1f7b8325---moponukuxinuf.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/b5e5750559dd172e96505b7da31bf458/93115853453.pdfIn PDF document text
    • https://aslimitada.com/userfiles/file/lavokezafixilizo.pdfIn PDF document text
    • https://grafitpoint.ru/wp-content/plugins/super-forms/uploads/php/files/d31d4fdc6998647ec075bd7582159653/walawiwazesonifan.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16070358f39d64---43891031596.pdfIn PDF document text
    • https://pensionatiitalianiinportogallo.it/wp-content/plugins/super-forms/uploads/php/files/025830403ed32d2111997537bf692342/lilumisokomuzivufupi.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a253b79429---wopex.pdfIn PDF document text
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/24b1e1fe179f621d20e0647be5a0cbb2/2952213661.pdfIn PDF document text
    • https://deconkhoemanh.com/wp-content/plugins/super-forms/uploads/php/files/5e428fl8vbvhuutpp31jnlmb7l/jojasizumexafomika.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099788a28aa9---tewutovudodo.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609f0822a4de3---fefuforogenajavinufam.pdfIn PDF document text
    • https://tripleccompanies.com/wp-content/plugins/super-forms/uploads/php/files/3ffd5a04c2d3a7d5c47f4e0578573d10/fuzosavatojekapu.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/39c875f0b68076418f9301e43b167389/lewisezetulavatepon.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_off0000d240.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD240 5984 bytes
SHA-256: 78b8d7c47a6e8c012729b2f37cf679f156323a6ade673f59b0410152d315397a
font_01_sfnt_off0000e674.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE674 9792 bytes
SHA-256: 5b93044823088344edb5eea9a0fdbf77ef1e679c42760990d7d1a69a09cd935f