Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9c4c6b7daf2f004…

MALICIOUS

PDF

83.8 KB Created: 2021-03-28 07:27:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 70eb1be2043691c437de07cf8637358b SHA-1: 12aff8519f29d31a52cdab2f2d5ec8e3f9aef52f SHA-256: b9c4c6b7daf2f004cf0e0f2516c52f2904d8de97019ba5e23c69081310077819
186 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many pointing to disposable hosting, indicating a link farm designed to distribute malicious content. ClamAV detection and ML classification strongly suggest this PDF is malicious, likely a phishing or trojan distribution attempt. Although no scripts were explicitly extracted, the PDF structure and URL patterns are indicative of malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://seumenha.ru/123?utm_term=descargar+diccionario+biblico+catolico+para+android+gratis PDF link annotation
    • https://lututigit.weebly.com/uploads/1/3/5/3/135335707/9e6748.pdfIn PDF document text
    • https://mizijuwewis.weebly.com/uploads/1/3/4/3/134392366/2600558.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420037/normal_60390d9a786b2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4452835/normal_5fe52d8065d2e.pdfIn PDF document text
    • http://nikecortez.net/molaxadoderumurcdwe.pdfIn PDF document text
    • http://changepass.online/ukulele_strumming_patterns_4_4d4fg6.pdfIn PDF document text
    • http://atomlinux.com/40531516103i3uvc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4424328/normal_5fd172ed9356f.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://a121017b-3fb3-450c-9156-48dd71a9bf80.filesusr.com/ugd/07625c_b324371d1c8e4e51b1a801d1df2fd823.pdf?index=trueIn PDF document text
    • https://80c93ba6-74df-4afb-9852-3a83eaba20e3.filesusr.com/ugd/4cf28d_6e03f7e95046417cbc59c5dd991c710b.pdf?index=trueIn PDF document text
    • https://3485775d-af35-4505-8fb4-f6750f575e04.filesusr.com/ugd/42f18e_15b461d258ba4ed98556fa3d0e6ab2f5.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/jevopemosod/html_templates_view_source_code.pdfIn PDF document text
    • https://40ba1f7a-6e91-49bb-bbb8-dfbb40a2bc60.filesusr.com/ugd/22bf55_f4fa8fc1b3aa4c499702cc0ed22204be.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tobojelusiwi/amortization_spreadsheet_excel_template.pdfIn PDF document text
    • https://9c3086b9-336b-4a4d-b39c-975a2563a2e0.filesusr.com/ugd/f4f792_4c43c9714ce14d029b49195a5eb540c9.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xalexojaxipud/pyramid_principle_barbara_minto.pdfIn PDF document text
    • https://82cb18f6-4a40-4824-ac11-10070f72ce02.filesusr.com/ugd/5aec95_70b51c67fb3a4c3e94f2bdeeeee20cca.pdf?index=trueIn PDF document text
    • https://d80868e2-5d34-4dda-9345-0396294a35aa.filesusr.com/ugd/f9fac6_00447dd6a51b4d4f8b05c0e810238550.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/telasebisu/98502176252.pdfIn PDF document text
    • https://9e730ba1-499c-413e-9a09-8a81f8121270.filesusr.com/ugd/0a0016_513e18e0b0b44bcd92685371339d9030.pdf?index=trueIn PDF document text
    • https://a86a6b26-b473-4b55-b9aa-7628a2bff077.filesusr.com/ugd/4f270c_1235949cd92f4b35a44dcfdf5204e524.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tirimofufemukat/76640054702.pdfIn 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_off00010618.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10618 5380 bytes
SHA-256: 121416e06f7f27e3c1aec7c43d54782482b400359eece24b27bf0190e0d1556e
font_01_sfnt_off0001186b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1186B 12052 bytes
SHA-256: 9a18258fa634ebb31dfb08de6a2fc525a6d7a14c8c290d0ece8d0248abb31730