Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b28ccce92e64132…

MALICIOUS

PDF

119.6 KB Created: 2021-05-15 16:05:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 4b111b80a14641ad8c4f8af07db780ca SHA-1: e3e6f80bfe7ada4153d8a9056c0b3445f88189ae SHA-256: 8b28ccce92e64132e83d1af040769f69df02df632a1a49096961fcb187bde1c5
184 Risk Score

Malware Insights

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

The sample is a PDF file flagged by multiple heuristics as malicious, including a critical finding for linking to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, suggesting it was generated programmatically. The numerous embedded URLs, many pointing to disposable domains and redirectors, strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://dafemum.ru/strik?utm_term=manual+de+funciones+del+director+de+la+escuela+primaria In PDF document text
    • http://momentikshop.space/free_printable_christmas_logic_puzzlesso1z7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387420/normal_6036f25dcd333.pdfIn PDF document text
    • http://murezisafedamaw.22web.org/badikanavefopeli.pdfIn PDF document text
    • http://takovevagagiv.scienceontheweb.net/ruruzixovotogidiwefezoba.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367311/normal_604336a87b35b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415936/normal_6025f86d5546f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387815/normal_603c2a78eeab0.pdfIn PDF document text
    • http://pukimupupe.22web.org/scrum_values.pdfIn PDF document text
    • http://piredvizhnik.com/jurassic_park_theme_piano_sheet_musicqzwb3.pdfIn PDF document text
    • http://sowinod.mywebcommunity.org/analytical_geometry_of_three_dimensions_book_free_download.pdfIn PDF document text
    • http://revershjtb.site/92911366937ke6lq.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464072/normal_6063cf8561280.pdfIn PDF document text
    • http://bunagutafa.getenjoyment.net/math_problem_solving_for_grade_4.pdfIn PDF document text
    • http://jugapus.sportsontheweb.net/basic_dslr_photography_tutorials.pdfIn PDF document text
    • http://puditutado.22web.org/malcolm_baldrige_modelo.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/eb83798a-84ad-4267-9f84-8163a674cceb/how_many_calories_in_a_small_krispy_kreme_donut.pdfIn PDF document text
    • https://e8e87dc5-637d-47ba-9de6-e7d98d123d78.filesusr.com/ugd/a69a03_d6f23d0e85cd4b81ae07067596030633.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/f6036608-be05-477e-85e8-d02f3c3afdb4/sony_handycam_hdr-cx405_review.pdfIn PDF document text
    • http://galukovo.epizy.com/funciones_del_texto_argumentativo.pdfIn PDF document text
    • https://c788b29d-df2d-4d46-9946-349e8cce89b7.filesusr.com/ugd/a9e086_6b75026af2a148f9a8d8a8b5d8f2fb81.pdf?index=trueIn PDF document text
    • https://a3e8d6b6-68ee-4625-a313-a25a09dbd39d.filesusr.com/ugd/312e12_835289be2b6149fb978869a26be31d65.pdf?index=trueIn 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_off000180ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x180EE 5304 bytes
SHA-256: a7b084194a404009a712c1f7cce2ad9833d8013b841373da9890057ac5f745cd
font_01_sfnt_off000192f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x192F5 11624 bytes
SHA-256: 249ef3299d5af32dca215d2594392ec276fa59adec55bb5cd8af8184975d8bc7
font_02_sfnt_off0001b899.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B899 16112 bytes
SHA-256: 04c641d0aedeaa8c494855f42a2e9ae6fad9e3679126e7dc5c08fccc4b41c292