Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c4f759bd0ab59dd…

MALICIOUS

PDF

74.0 KB Created: 2021-06-10 10:06:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 30b489bd12f5ddd3253570bfb44b8bf0 SHA-1: c5104c2eb878a3c79e79ba5e5e4f447b1655827d SHA-256: 0c4f759bd0ab59dd6b1ade3de283c347859f6da82b44207b8f1b05fd2e2b2897
126 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, with a high-confidence heuristic flagging it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The primary malicious URL identified is https://krisoc.ru/pbw, which is presented in the context of a 'best psp game list'. No scripts were extracted, but the PDF structure itself facilitates the redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://krisoc.ru/pbw?utm_term=best+psp+game+list PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4413473/normal_6002e995a8c32.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465000/normal_5ffdf1f48734a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4381094/normal_60bbdb60ef409.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477163/normal_6064bc66ddc43.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485322/normal_601c6a1139b3c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391621/normal_60c1abc3a4c3d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4477369/normal_5ff6910ee95ce.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://wotasaful.pbworks.com/f/xajajexofuzotakuk.pdfIn PDF document text
    • http://rixepal.pbworks.com/f/touchstone_4_unit_11_quiz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ec9ed479-ffd9-4eaa-8660-e3e6ba7fbb39/lg_unlock_code_generator.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a74d618d-2bd1-42a8-a225-fe5fe5eeb26e/03.06_employment_and_occupations_writing_assignment_answers.pdfIn PDF document text
    • http://wirajudukim.pbworks.com/f/wivoraxo.pdfIn PDF document text
    • http://kokoxudalux.pbworks.com/w/file/fetch/144426957/how_to_turn_on_wd_my_cloud_ex2_ultra.pdfIn PDF document text
    • http://kufepizerix.pbworks.com/f/goethe_zertifikat_b1_schreiben_teil_2.pdfIn PDF document text
    • http://kaborope.pbworks.com/f/wovadigorudogabep.pdfIn PDF document text
    • http://jujirafamena.pbworks.com/f/wisevenebikeponalajiwater.pdfIn PDF document text
    • http://xobapotowi.pbworks.com/f/how_to_highlight_duplicate_values_in_google_sheets.pdfIn PDF document text
    • http://ridelox.pbworks.com/f/lalesoxopadisujuwibarake.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/33bb593e-ff11-4f93-aa69-3c5e26255307/giranuder.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cc86fe8e-ebf0-4b0f-ade0-94601c5daf3d/jogago.pdfIn PDF document text
    • http://funesut.pbworks.com/f/worksheet_3_graphing_exponential_functions_answer_key.pdfIn PDF document text
    • http://pusurupufem.pbworks.com/f/una_carta_para_mi_novia_en_su_cumpleaos.pdfIn PDF document text
    • http://zupelapowi.pbworks.com/f/degobalafus.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3cf7f79f-91bb-49f9-8fe5-0a2627df88ac/ejercicios_con_verbos_regulares_en_pasado_simple.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_off0000e3ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3AB 5092 bytes
SHA-256: 0e34217c98b302ad6705365f9957fe006e9eb200c47749d529d0bf1ccbc072bc
font_01_sfnt_off0000f4f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4F2 10592 bytes
SHA-256: 453a149452febd2d479b35792bcce1b242ec543c6ef50ee888328ef00382cc12