Malicious PDF — malware analysis report

Static analysis result for SHA-256 dea6f7ff811a8334…

MALICIOUS

PDF

91.9 KB Created: 2021-04-19 22:34:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 4f860d784a5d63e40b6f8ad806cad35b SHA-1: d56db9d006dbdf9b0def13b3de7a7c1d96107253 SHA-256: dea6f7ff811a83344420d76a3ecf8888050c602da31a3ea58fdd922efb3631c4
134 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous external URIs, many hosted on disposable domains, forming a link farm. One prominent URL, 'https://nipisod.ru/strik?utm_term=sony+fs5+mark+ii+firmware+update', suggests a lure related to a firmware update, likely to trick users into downloading malware. No scripts were extracted, but the PDF structure and URL patterns are indicative of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://nipisod.ru/strik?utm_term=sony+fs5+mark+ii+firmware+update PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4497109/normal_601855320e32a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4394066/normal_6033d91bd425e.pdfIn PDF document text
    • http://jekeluxuto.mywebcommunity.org/wonexetogur.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4498882/normal_5fcaab3c05c37.pdfIn PDF document text
    • http://gekifek.scienceontheweb.net/73823817115.pdfIn PDF document text
    • http://zuzorovix.scienceontheweb.net/43958984111.pdfIn PDF document text
    • http://mebevevi.mywebcommunity.org/fundamentals_of_the_faith_lesson_2_answer_key.pdfIn PDF document text
    • http://vevapefin.sportsontheweb.net/rrb_bangalore_alp_cut_off_2020.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379842/normal_6035b6bc44a4e.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/a5344f95-4401-48e9-a015-4824c1b8604f/jujemolepuxumutaxetoses.pdfIn PDF document text
    • http://kagijido.myartsonline.com/apa_cite_generator.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/97c73487-c8df-4be7-bb46-f026c8e5a770/56943515618.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/57fbd959-2435-4908-b42e-b78c644d1da7/where_was_princess_diaries_2_filmed_genovia.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a5f4ca21-d77b-4cf1-bb50-9e4923a1230a/rufirativiluwedi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/66ac2b94-87cc-4024-ab71-53f69c7f06dd/19838577315.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b0327f2c-251e-42c9-899d-70fd4aa5a766/what_communication_style_is_required_in_this_type_of_situation.pdfIn PDF document text
    • http://lobopekogolo.onlinewebshop.net/shri_durga_argala_stotram.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d62bcb98-566f-4964-97fe-0af8dce5a63d/99972862438.pdfIn PDF document text
    • http://pudosuvosav.atwebpages.com/hunger_games_chapter_13.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cbc32c88-46f2-4731-a5b7-1b1943b6c440/bair_hugger_775_service_manual_deutsch.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011c00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C00 2960 bytes
SHA-256: 4c688c0676da4c9c3f1d636d29496b85ed1f90b4285ee9b780884cc7de0e34ac
font_01_sfnt_off00012670.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12670 5640 bytes
SHA-256: 03289f0a00594e4cc7158a02ffccaae24bc254a95562d230b1d9875f7b0b4eef
font_02_sfnt_off000139b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139B2 11672 bytes
SHA-256: 6796c51c42446315c7f9819b192b8f792b641c87755f4c3f8e2de02595af60b6