Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f5ae75461ea76bd…

MALICIOUS

PDF

48.3 KB Created: 2020-10-04 12:00:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 52c388d9d425ddb690b8746e76f9a859 SHA-1: f57ac43a53eea280bd1f308e47e822879356060e SHA-256: 8f5ae75461ea76bda45b8f68d3d638e7dfd8ef7d7a366091c7e7df822a3861fe
184 Risk Score

Malware Insights

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

The PDF contains a link farm designed to appear as a free PDF to Word converter, but the primary link redirects to malicious infrastructure. The ML classifier strongly indicated maliciousness, and the PDF structure is consistent with SEO-based link farms used for malicious redirection. No scripts were extracted, but the embedded URLs and heuristic firings clearly indicate a redirection-based attack.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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 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.
  • 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://gettraff.ru/strik?keyword=convertidor+de+pdf+a+word+full+espa%25C3%25B1ol+gratis In PDF document text
    • https://site-1037896.mozfiles.com/files/1037896/68765697932.pdfIn PDF document text
    • https://site-1036724.mozfiles.com/files/1036724/44785810581.pdfIn PDF document text
    • https://site-1038337.mozfiles.com/files/1038337/56354154733.pdfIn PDF document text
    • https://site-1039556.mozfiles.com/files/1039556/29156999481.pdfIn PDF document text
    • https://site-1037207.mozfiles.com/files/1037207/semoxigesozimusofobigafa.pdfIn PDF document text
    • http://diguz.dental-public-health.com/uploads/1/3/1/4/131482952/vagavigik.pdfIn PDF document text
    • http://lezovi.dongesbaypto.org/uploads/1/3/1/3/131379578/5246797.pdfIn PDF document text
    • http://files.glassfarmgreens.com/uploads/1/3/1/8/131871762/6a0e9.pdfIn PDF document text
    • http://files.deweybookemhowe.com/uploads/1/3/0/8/130813409/kisidep.pdfIn PDF document text
    • http://zexuxuxel.daveolympics.com/uploads/1/3/0/7/130775705/fitifuxivedaf-talagiwuse-waxamegefepozid-sijebotigumi.pdfIn PDF document text
    • http://files.spiritofvenice.info/uploads/1/3/0/9/130969632/28fb20ae.pdfIn PDF document text
    • http://kusiw.adglresources.com/uploads/1/3/0/9/130969823/xabosixe.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/d19dd212-7d08-4aa7-ab22-c5fd8d99aac0/wajununogiraxo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cc8c1f29-2cb8-4b43-8b08-9c521e758cab/49412341912.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5fe6740e-8bf2-44b6-b327-0fe3f2c50f2d/89112152816.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/552a4a23-b47a-44a8-8ccf-996cb87a3f83/danes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/126fca71-d984-473d-96ab-95162f5d394f/62758926863.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_off000071cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x71CB 3048 bytes
SHA-256: 72bffb912a88d0f2ad9d78e34158d12540833c82e5d0c70e324fd0e012a5c479
font_01_sfnt_off00007c9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7C9E 5480 bytes
SHA-256: 3ed9fe43e4b8d29c9c8ac2c5a7ce2dde0ee6a2a920ecdee7ac16c1333ca08626
font_02_sfnt_off00008f22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8F22 10044 bytes
SHA-256: 45af5c074b1f19817a885764e3c1a56f1d902087a8292501772ae1016864bbb2