Malicious PDF — malware analysis report

Static analysis result for SHA-256 25163f572fb267a7…

MALICIOUS

PDF

81.4 KB Created: 2021-03-16 15:09:46 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: b72bd99573349da9d4b3c82ad5b40a19 SHA-1: f52164315fdc455838f9b7a691462a8538748ca0 SHA-256: 25163f572fb267a705671815fb654391c586e997e643690b95fb9bc90f62b9c6
126 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to disposable hosting and are used as link farms. One prominent URL, 'https://vilenefex.ru/strik?utm_term=realtek+hd+audio+manager+subwoofer+not+working', is directly linked to a heuristic firing indicating a phishing attempt related to audio driver issues. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to a phishing or malware download site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

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://vilenefex.ru/strik?utm_term=realtek+hd+audio+manager+subwoofer+not+working PDF link annotation
    • http://xozonline.ru/dokasijonodisari917u7.pdfIn PDF document text
    • http://raisinshub.pro/vazebonodozixepu1lty1.pdfIn PDF document text
    • http://sodahub.pro/skyrim_how_to_get_smithing_up_fastv1lns.pdfIn PDF document text
    • http://therarbooks.com/34638812278xdigs.pdfIn PDF document text
    • http://egrn-order.online/systematic_desensitization_data_sheetx86by.pdfIn PDF document text
    • http://pejazadajenatew.getenjoyment.net/authorship_of_the_bible.pdfIn PDF document text
    • http://redtea.space/60630202695a44j7.pdfIn PDF document text
    • http://kindraretterath.com/xusexig1v81t.pdfIn PDF document text
    • http://robolab.one/asian_stock_markets_futures9ki1a.pdfIn PDF document text
    • http://testrun.ru/who_is_lady_marys_second_husband_on_downton_abbeynis0r.pdfIn PDF document text
    • http://domainlimax.xyz/casio_gzone_commando_4g_lte_c811_specsuidko.pdfIn PDF document text
    • http://kieverts.xyz/ninestars_trash_can_lid_stopped_workingqntfh.pdfIn PDF document text
    • http://souve.me/39370790239ygitp.pdfIn PDF document text
    • http://popularchoice.space/zagibimelawuwelopituboremwh101.pdfIn PDF document text
    • http://bcpreactiva-enlinea.com/33696125874pol8.pdfIn PDF document text
    • http://ukrinsure.com/ririputodjwlxe.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/c19bd635-36e6-47d7-be58-ce93cb4cdc8a/tabla_de_densidades_del_agua_a_diferentes_temperaturas.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/feee844d-79bf-42b2-b705-f5dd3f25a6c1/estandares_y_expectativas_de_estudios_sociales_2018.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/678e4a1d-08ad-488f-8377-b2ef9d1badc1/81218252546.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6c4127df-c199-4b35-8bd2-e77f09981fae/77727798765.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/af45cc26-4373-484a-bcdf-93004759ad4d/geometry_formulas_for_ssc_cgl_in_hindi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3755c469-d07d-4c7e-9a0d-471027e5383a/libro_de_significado_de_los_sueos_para_descargar_gratis.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/55c1cec4-a19a-450d-b5d2-bdd9eaa51088/vutejika.pdfIn PDF document text
    • http://muluwokixo.onlinewebshop.net/annotate_files.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/74178cd1-d81f-493f-8a35-8fb251767dec/memento_mori_jewelry_skull.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ffff8a57-04fa-43ca-9784-fa37bf740621/nukemej.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_off0000ff9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF9F 5624 bytes
SHA-256: 49fa2ed20d87e4d37272b35bf9e75d77a5dd314b2795aec4da82e0d81cf91fc1
font_01_sfnt_off000112a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112A4 10904 bytes
SHA-256: e7aa216226b1acca2ea534a0456caa659df1cdab642fc9ded561d87e9f98492d