Malicious PDF — malware analysis report

Static analysis result for SHA-256 528cf0538b2fa5ae…

MALICIOUS

PDF

74.7 KB Created: 2021-06-10 07:05:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: b67dad98d2f6dc65995f7eb7949d7a08 SHA-1: c3247f9ab542105f80ffc5ebb74fb9e25bef7572 SHA-256: 528cf0538b2fa5aeca9ab6afc4aa8d629efb88e870d7030cfcc6bfe397529e99
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a link farm with numerous external URLs, suggesting it's designed to redirect users to potentially harmful websites. The presence of embedded URLs and the PDF_SEO_LINK_FARM heuristic further support this, pointing towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://ketchas.ru/pbw?utm_term=the+boy+in+the+striped+pajamas+questions+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4387706/normal_605d904546262.pdfIn PDF document text
    • https://kurokeduzuw.weebly.com/uploads/1/3/4/6/134693898/katomibojuvur_ruwemera_mupufit_sebomezaluk.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365567/normal_603c037ba7320.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4467910/normal_6004e89230c41.pdfIn PDF document text
    • https://segurabo.weebly.com/uploads/1/3/5/9/135964373/fisufamijesisa.pdfIn PDF document text
    • https://lubikumak.weebly.com/uploads/1/3/1/4/131453733/6563826.pdfIn PDF document text
    • https://doxorovovo.weebly.com/uploads/1/3/4/4/134479089/xedilapamodapikubadi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4455672/normal_605b75fd95ec7.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://gaxoxim.pbworks.com/f/93338339995.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/41b2594a-e9b0-4a63-b45d-7424e2a57ba3/is_wicked_appropriate_for_a_10_year_old.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a8eb6fe8-4b53-499d-9e76-00db84abf561/20342424339.pdfIn PDF document text
    • http://davukuzu.pbworks.com/f/how_to_fake_a_call_on_iphone.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/659530f0-b01e-46d1-9584-588e096e373c/towerudixifukar.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/39453a4b-58e1-4b70-a9ab-b43ebe98a920/constitution_of_nepal_2072_in_nepali_date.pdfIn PDF document text
    • http://kukuwowuxen.pbworks.com/f/logo_quiz_level_33.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d60577fa-3383-4607-9c83-77e04dc9678f/69107183909.pdfIn PDF document text
    • http://dobifapig.pbworks.com/f/how_to_put_npcs_in_piggy_build_mode.pdfIn PDF document text
    • http://noxiwako.pbworks.com/w/file/fetch/144819921/jbl_charge_4_vs_ue_megaboom_3_sound_quality.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/28bfa6ad-8c14-4e97-a310-fab238dc2d45/how_to_activate_autocad_2020_student_version.pdfIn PDF document text
    • http://sisagexal.pbworks.com/w/file/fetch/144611457/tithi_toran_gujarati_calendar_2017_download.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_off0000e6ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6EE 5644 bytes
SHA-256: 03b9e91b89ffebf53f737b97a1f6d1189ec08e63d5fad21a2e01b83d95a744c6
font_01_sfnt_off0000f9f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9F1 10612 bytes
SHA-256: 28e355fad101d7def78e5cada67166f46044641f21fcf08ff11a869eaea67ce2