Malicious PDF — malware analysis report

Static analysis result for SHA-256 90d8c25acbc7f579…

MALICIOUS

PDF

75.2 KB Created: 2021-06-07 08:08:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: d8cde5ea61993363611adb1ce7a25138 SHA-1: 2e5ec7b0a3f4fb7acc5ec57cc5cd21f94afa2a6b SHA-256: 90d8c25acbc7f5798d1d3d8c7e7115670bac997061f4db7997b65cee99f188f1
156 Risk Score

Malware Insights

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

The PDF document contains numerous links pointing to compromised WordPress sites, suggesting a phishing or malware distribution attempt. The 'ML_NYX_PDF_MALICIOUS' and 'CLAMAV_DETECTION' heuristics confirm its malicious nature. The document body, though heavily obfuscated, appears to be a lure related to an 'exercise', likely to trick users into clicking the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • 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://medvor.ru/uplcv?utm_term=exercice+ce2+s+ou+ss PDF link annotation
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/160afc0d8051b1---48194454592.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c96e22c7b5---waxijonebemovapuvifew.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/a4r894e6v5m3gb44urllamvv46/42792236932.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609d4214506a8---74735785078.pdfIn PDF document text
    • http://suamayin.biz/userfiles/file/xopezokipizogivorulawas.pdfIn PDF document text
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/305rslssngp291vqb4pgdqsag4/xogumo.pdfIn PDF document text
    • https://alihuata.com/userfiles/file/vezodexavujasukij.pdfIn PDF document text
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd202ad63e5---18333346847.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/013cfcadc784151fec65b4a2c828d755/kezebozajixovikazuluga.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160975bba6f6b8---lesadedixebomujarize.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/426a3aed01748042f506a045e601ac4d/pulurijofogotutirigukil.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607aaac70f780---netalufaliribojasitunade.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b79e782464---59418722476.pdfIn PDF document text
    • https://ancoraeducacion.com/images/22201887094.pdfIn PDF document text
    • http://lamachine.nl/userfiles/file/13564115625.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c19512c3a3---33247575955.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7563e5e998---wixulura.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000e6be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6BE 4708 bytes
SHA-256: 37f1a19589c593999f68869a452eb787ad7340e8a0b197c55b06fd9ae2f02304
font_01_sfnt_off0000f6df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6DF 12380 bytes
SHA-256: 968b6b76f30595372b4368c5c495192d44b12df2c7351d8604631463ab7f2a47