Malicious PDF — malware analysis report

Static analysis result for SHA-256 831d875661ff5754…

MALICIOUS

PDF

52.0 KB Created: 2020-10-06 19:14:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-10
MD5: 286ce8c916b0afb1503de46785312506 SHA-1: 86cb834f8fe1edeaed7999ab8ff6a7d55c826d52 SHA-256: 831d875661ff57542a3b68529026db3fdb3bd4e0accf6d281d5c2162644c11e6
124 Risk Score

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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://cctraff.ru/strik?keyword=exercices+atomistiques+pdf In PDF document text
    • https://site-1036881.mozfiles.com/files/1036881/jofuxo.pdfIn PDF document text
    • https://site-1040282.mozfiles.com/files/1040282/safitoranuwaxosale.pdfIn PDF document text
    • https://site-1041084.mozfiles.com/files/1041084/rodapuxasunijibogob.pdfIn PDF document text
    • https://site-1039226.mozfiles.com/files/1039226/83331869140.pdfIn PDF document text
    • https://site-1036725.mozfiles.com/files/1036725/31643012278.pdfIn PDF document text
    • https://site-1039848.mozfiles.com/files/1039848/nemed.pdfIn PDF document text
    • http://files.christchurchdartmouth.com/uploads/1/3/1/0/131070520/nipopuguwalek.pdfIn PDF document text
    • http://files.psideltaalumni.org/uploads/1/3/0/7/130740490/709eaa.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/b3030142-bcd8-4c8e-b133-b5b09fb4ddd9/35304798333.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7358241b-d7f0-4906-a610-1cdf36bdcfc9/92009402788.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/23c38163-3948-40a0-b751-6410234244d6/tufimeriwalumonogowale.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_off00008d39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8D39 5420 bytes
SHA-256: 1c81435642e2cef95dd5d84e73090ce0a9455eed648142a2c777438c52a8ea98
font_01_sfnt_off00009f99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9F99 10516 bytes
SHA-256: 428b27b3a85f6cc8c5ffe1f8c029693e14081d1d4d05b29763bcf21161892bad