Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb681e845b6d9b91…

MALICIOUS

PDF

85.5 KB Created: 2021-03-07 12:50:51 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: df1b4b39058c2cce7b32f61581b6c9cf SHA-1: c4d91d0f2b92f4fa18bf42aba99454b8dda344f1 SHA-256: cb681e845b6d9b91d87f17123661fbae70d20d9e7bfac248b40f735d0ed0b0a5
184 Risk Score

Malware Insights

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

The PDF file contains multiple embedded links that are identified as malicious redirectors. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM suggests the document is part of a link farm designed to distribute malicious content through disposable hosting, aiming to trick users into visiting harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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
  • 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://crophysi.ru/strik?utm_term=problemas+educativos+actuales+en+m%25C3%25A9xico+2020 In PDF document text
    • http://cardio-active.site/vizio_m50_c1_main_board3bv5t.pdfIn PDF document text
    • http://luchdobro.site/72284020161qqooi.pdfIn PDF document text
    • http://stav-games.ru/the_essential_life_book_australianeulz.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4453142/normal_5fcedbab05f8c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4476577/normal_60047adeb9c2e.pdfIn PDF document text
    • http://fofiwafajelerax.sportsontheweb.net/33724272405.pdfIn PDF document text
    • http://arm-watch1.club/kexipasowiluxezavodig78fg.pdfIn PDF document text
    • http://maykistore.ru/simple_past_exercises_intermediate5kk12.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4527237/normal_60251af60d880.pdfIn PDF document text
    • http://pipavinekiga.mywebcommunity.org/gimolajofugutewakoxozera.pdfIn PDF document text
    • http://reduslim-shopofficial.site/android_edittext_rounded_borderb3e2n.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380078/normal_6030de22e8fb3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471514/normal_60310683d3f88.pdfIn PDF document text
    • http://fajiriduxir.medianewsonline.com/57305094102.pdfIn PDF document text
    • http://mokaxizekebade.scienceontheweb.net/formulas_para_el_volumen_de_prismas_rectos.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/585f58fc-def8-4434-9283-e0aab33c60c3/dark_souls_3_review_ps4.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ba951d5b-b16f-4bf7-af1c-a90f279dc693/how_to_test_a_dometic_rv_thermostat.pdfIn PDF document text
    • http://bototiluwoge.atwebpages.com/sharp_aquos_blinking_power_and_opc_lights.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fb132d56-00da-4480-8965-61fc61ca3dcf/ladokekuxekupide.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6ac537da-984d-4b9e-968b-b4c7114fe335/eddie_bauer_jogging_stroller_reviews.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fae0ec2a-ae16-44a3-9b24-c3c48fe6e69e/84596604.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/33131d41-465b-4289-b892-6a7faa3f34f6/best_mansions_of_madness_2nd_edition_expansion.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/450ad616-64ee-4686-932d-912439acf173/gepifasuzakojejixoroneser.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/62e5aee8-4b4e-44c4-a68c-a3202ffddd71/puxumewer.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/622b499a-27ca-46f4-a84a-f13904605421/misaxoj.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_off00010c49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C49 5768 bytes
SHA-256: 8cbd6361fc21268d0f247920cfafdfc5bd166c60a13c9fce9959bb408dcd5af0
font_01_sfnt_off00011f8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F8B 11660 bytes
SHA-256: b6af0b4265c01d9e650efda01de54962fd1bf2eb6668c9fd0f5b66ffbec59886