Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f8b33b7159cebb6…

MALICIOUS

PDF

81.9 KB Created: 2021-06-24 11:07:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: 44743037cf430ef66adc3b90a78538fa SHA-1: e2481f9cd60adcb2cbc531a8ff569db789b2449c SHA-256: 3f8b33b7159cebb6759d3a1a8c6ed96e592c198486be64c90122eb4689a6760d
156 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 WordPress installations, suggesting a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, potentially leveraging embedded JavaScript for further actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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=interview+answers+in+english PDF link annotation
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079290c4fe6a---16873485682.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c888d10ec74---teleboxafolawu.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/4g1a36mah4sctvrt98slui52bg/buworomamupuvetukimalura.pdfIn PDF document text
    • http://kardelendalgicpompa.com/uploadfiles/file/ribovavunotudepar.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095cbf1b4879---damizajatigabi.pdfIn PDF document text
    • https://al-farh-iq.com/upload/userfiles/file/12518568668.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16072f6bbdfce7---34440522869.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/160834b4d5bb46---gasifuwis.pdfIn PDF document text
    • http://kenshopvn.com/uploads/files/83154212361.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/o6dgu8caole7arpai7p4m0hpe3/fixofosav.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095affc3427d---fipifozem.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/125fc9994d16adf1b534757d678030ae/77802470448.pdfIn PDF document text
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ad11bdc206e---gitunito.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/ebaaadjnmm7duniu72j6shvq75/54667143521.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_off0001026c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1026C 5036 bytes
SHA-256: 227ce1e9d251209a71cf740119b398783ddac03327daa823095ec92bfc177367
font_01_sfnt_off0001139b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1139B 11500 bytes
SHA-256: 764ade9e2de1e908a45f320d883c3098d6e47852c9626175ac56d675c4056a81