Malicious PDF — malware analysis report

Static analysis result for SHA-256 21cfd5f990815cae…

MALICIOUS

PDF

74.2 KB Created: 2021-06-01 10:14:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 6639aab634530351b04aad08394e106c SHA-1: 595e52fec27e9458b1bce18eb310aa8a9bb53e05 SHA-256: 21cfd5f990815cae7585fb3aca8cae1e667d00629cda1408f0ae9c213c3d7f20
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with a significant heuristic indicating it's a link farm on disposable hosting. The primary malicious URL identified is https://kuzutuzo.ru/123, which is likely used to redirect users to a phishing or malware distribution site. ClamAV detection and ML classification strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://kuzutuzo.ru/123?utm_term=fester+acriton+resanador+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4403141/normal_606a0119c2f6a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411944/normal_60489b2f5c914.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4500897/normal_5fed4c070d1d4.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4477401/normal_6002f2b71efd1.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/57698600-7f9b-42df-b02f-af88298b76d7/the_other_side_of_the_wind_dvd.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/85c1b419-4a0c-486f-95b6-c9c5b9deaedd/rugadizikapirimeluwipe.pdfIn PDF document text
    • http://xofitesu.pbworks.com/w/file/fetch/144448215/solaxojubad.pdfIn PDF document text
    • http://mumubib.pbworks.com/w/file/fetch/144413322/cambridge_first_certificate_in_english_3_with_answers.pdfIn PDF document text
    • http://degenazi.pbworks.com/f/how_to_get_adt_panel_to_stop_beeping.pdfIn PDF document text
    • http://bovojigu.pbworks.com/f/79832252368.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dfa80b26-d63c-4360-86f9-5968c489a3d9/88473843953.pdfIn PDF document text
    • http://nefusim.pbworks.com/w/file/fetch/144438807/44399652582.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5fa91f6d-ec80-43ba-b51e-a9e35373ecc3/symbol_scanner_programming_sheet_ds6708.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/af063bde-88bf-4159-951a-d60e16c97d2a/daily_art_challenge_2021.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8cb02f31-494f-4267-a17f-abc698f3b6b0/77332097186.pdfIn PDF document text
    • http://rugewenuzed.pbworks.com/f/how_can_i_apply_for_inter_caste_marriage_benefits_in_karnataka.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7cae91f2-7631-45ac-a780-ddb547327b00/87424277549.pdfIn PDF document text
    • http://zelovoguvunu.pbworks.com/f/arc_length_area_of_sector_worksheet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/72fd69ae-a94a-4e70-a906-d086844a15a2/list_three_common_characteristics_of_living_things.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cc5537b0-427c-471d-895d-120f3ffa2ae4/51556543911.pdfIn PDF document text
    • http://xujefix.pbworks.com/w/file/fetch/144417213/mowovufubepepar.pdfIn PDF document text
    • http://fixunomavow.pbworks.com/f/principles_of_managerial_finance_14th_edition_solutions_manual_by_gitman_zutter.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_off0000e12f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE12F 5072 bytes
SHA-256: 5095601aae7e4b6d4f928d870478181387932679ad0e8518f0c454c356630274
font_01_sfnt_off0000f282.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF282 11860 bytes
SHA-256: 7ac324c0bf6baca28d095c15f912ed06e5315e9c64e89ee889086da071cbc9d2