Malicious PDF — malware analysis report

Static analysis result for SHA-256 13443894227ec95f…

MALICIOUS

PDF

73.0 KB Created: 2021-03-28 00:32:24 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: 9428643e663e8c134907045036f2cde4 SHA-1: 05f19a9ed797ba1b6c83e8f5ba5a07dc15cc7234 SHA-256: 13443894227ec95f7e0a6c7f1fc2429b9a02618e8960249596f1d3012688cce2
186 Risk Score

Malware Insights

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

The sample is a PDF containing a large number of external links, identified as a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. The embedded URLs, such as 'https://kuzutuzo.ru/award?keyword=belajar+membaca+tanpa+mengeja+pdf', are used to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • 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 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://kuzutuzo.ru/award?keyword=belajar+membaca+tanpa+mengeja+pdf PDF link annotation
    • https://zivadufo.weebly.com/uploads/1/3/0/8/130874541/pumeluxa_sefimuseluzitor_donaxilusekixo_motase.pdfIn PDF document text
    • http://opt15.ru/tosifajavasafunubale73gc3.pdfIn PDF document text
    • https://rubajamepufukav.weebly.com/uploads/1/3/4/4/134432722/tanifobunejo.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464314/normal_605aa09d8f249.pdfIn PDF document text
    • https://makumagem.weebly.com/uploads/1/3/4/3/134373862/5690621.pdfIn PDF document text
    • https://tajerupabud.weebly.com/uploads/1/3/1/1/131164315/lovezufobatag_femovazupox_gesifano_fovube.pdfIn PDF document text
    • http://vexoxem.scienceontheweb.net/mabagera.pdfIn PDF document text
    • http://amin-ukraine.net/pinimuzinnpp3n.pdfIn PDF document text
    • http://stickerrus.ru/pifobozuvuroxafaxogqssbf.pdfIn PDF document text
    • https://borirokuve.weebly.com/uploads/1/3/1/4/131437567/gukitelowuvevimiv.pdfIn PDF document text
    • http://zujewubowufonug.scienceontheweb.net/jixalajoviwudotu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4505820/normal_5ff0d4dd686d5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4489607/normal_5fdfb3063d687.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://74df6fe0-557b-4e47-8461-f2df536053d0.filesusr.com/ugd/4dcf4e_6aed8bafb60b49e88fd543f3df6fd95b.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9ea372ba-dc8e-404b-b393-0d8e37257d79/best_advanced_excel_course_online_quora.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/62b49611-4744-449c-a09d-cba9971a2c05/what_cat_foods_are_grain_free.pdfIn PDF document text
    • https://63aa7d51-6c54-48cc-ac87-b710a0da19c3.filesusr.com/ugd/c8d394_b9961e03ce1b42bc87970eaeecc96fed.pdf?index=trueIn PDF document text
    • http://gogujigasad.onlinewebshop.net/88300831348.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6ba123ad-5af0-47be-9583-eef99a2d80a8/gomubakabadisoxurijumef.pdfIn PDF document text
    • http://vovojoj.atwebpages.com/hard_reset_kyocera_duraforce_pro_2.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f85501da-78ab-43b0-8d22-4a4e8e2a7a68/magnum_inverter_me2012_troubleshooting.pdfIn PDF document text
    • http://desujiruvomeb.myartsonline.com/32102340129.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_off0000df21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF21 5560 bytes
SHA-256: c1fcdd0ae39f4974e58094df6da14e9877392aad5fd40535ba7df142099c7fdd
font_01_sfnt_off0000f1f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1F6 10200 bytes
SHA-256: 74ba50bca67a0d4c743bbc597bd61b579a3b98f275b517e5addc77ccfdddd5df