Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a5c0bb923859f66…

MALICIOUS

PDF

78.6 KB Created: 2021-06-12 18:55:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 0a219e3bffbea2887de55791d49595e3 SHA-1: 3039db7966b7d255d9f9f347d792666adbd493d4 SHA-256: 4a5c0bb923859f6699e724cc99ea156b213170ba6044685514c1ed289b027570
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 large number of external links, many hosted on disposable domains, suggesting a link farm or SEO manipulation tactic. The presence of embedded URLs and the PDF_SEO_LINK_FARM heuristic strongly suggest the document's primary purpose is to redirect users to potentially harmful external sites, possibly for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://medvor.ru/pbw?utm_term=objective+english+sp+bakshi+pdf PDF link annotation
    • https://legipulevigo.weebly.com/uploads/1/3/2/6/132695741/notozom.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421970/normal_602ca774048b2.pdfIn PDF document text
    • https://kusipujetaz.weebly.com/uploads/1/3/4/4/134462876/8289e.pdfIn PDF document text
    • https://wogizepi.weebly.com/uploads/1/3/5/3/135388010/tafumo-pofoverevemexe-derukogoja.pdfIn PDF document text
    • https://nakakikixug.weebly.com/uploads/1/3/4/4/134490848/pikesuk-nogudilemidaz-bibir.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4456399/normal_5ffac55978ab7.pdfIn PDF document text
    • https://xopaluwejur.weebly.com/uploads/1/3/1/8/131857284/varoxovuzudurezaxe.pdfIn PDF document text
    • https://fapuwokezisojo.weebly.com/uploads/1/3/1/4/131453853/luxamuraxi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378853/normal_5fd5ff16a8cf8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489988/normal_603fb8c0f0ad5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4486537/normal_5ff6b9858537a.pdfIn PDF document text
    • https://pazixexawa.weebly.com/uploads/1/3/1/4/131437352/8e547888c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://bekojifutok.pbworks.com/f/67486383248.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ff5850a1-abff-474c-9d1c-80b64d4f26d8/best_traits_for_astronaut_career_sims_4.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/21862886-44e8-46ff-b8c8-59e8ddf6b918/bubigedumofugitusa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/81d6dc0d-3c3f-47e0-a038-39c2c5bdd463/oraciones_con_yet_en_ingles_y_espaol.pdfIn PDF document text
    • http://guwodav.pbworks.com/f/41264476096.pdfIn PDF document text
    • http://serawazeg.pbworks.com/w/file/fetch/145040655/dumpster_app_mod_apk.pdfIn PDF document text
    • http://fotowefufet.pbworks.com/f/33059749996.pdfIn PDF document text
    • http://memofemovo.pbworks.com/w/file/fetch/144477846/29726371658.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1df60af2-4d42-4bff-921d-e48a6d2455a9/is_thinkorswim_available_in_canada.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4efa4a94-e410-4f6f-b0f4-28aeee440a82/5645889535.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000de22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE22 5688 bytes
SHA-256: 12d05bfa5b35c5761ed0e18c8afbff8baaccd723c12695c424cb9d97f6955589
font_01_sfnt_off0000f18b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF18B 11024 bytes
SHA-256: 5f091034d6719de06d1bbbd1c9505f12d07449cd29adf96275c102ddfb43676f
font_02_sfnt_off00011752.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11752 16172 bytes
SHA-256: 6e699eab9a6fef16b3ea923df7b93ce1c5cbd97c7a594d359cd98c90be4a35f1