Malicious PDF — malware analysis report

Static analysis result for SHA-256 41231fe8cf5eb779…

MALICIOUS

PDF

70.8 KB Created: 2021-10-01 01:08:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 8381d56d93169868ad9b6f4d61c37a1b SHA-1: dcf1c5e558e7933cc2d29ea628121175f80a7d6d SHA-256: 41231fe8cf5eb7795b3deb081b3e2d8a6216d35b30e80457fc04af4735caf063
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to suspicious domains, suggesting it is part of a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to exploit vulnerabilities or trick users into visiting malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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://grupahatak.pl/admin/_fck_files/file/76478573728.pdf In PDF document text
    • https://aradmissions.com/ci/userfiles/files/lafeguxaridixujunoko.pdfIn PDF document text
    • http://www.rajpuc.pl/pics/file/65133385691.pdfIn PDF document text
    • http://xn--o79av69abka850ab6c.com/upload/file/202109280355380239.pdfIn PDF document text
    • https://biharlokmanch.org/userfiles/file/fusexosotepil.pdfIn PDF document text
    • https://weborder.cloud/userfiles/file///24269717077.pdfIn PDF document text
    • https://penzion-palice.cz/content/32619407582.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/2d67fcfb1c0b88b74f3ea7046a18e182/zatalidexakowizigetojufiw.pdfIn PDF document text
    • http://munnarteabungalows.com/userfiles/file/29549194981.pdfIn PDF document text
    • http://balatonfurediallatorvos.hu/userfiles/file/49124946120.pdfIn PDF document text
    • https://stancijanegrin.com/UserFiles/files/74424133543.pdfIn PDF document text
    • http://ciaomamma.hu/editor_up/83407918194.pdfIn PDF document text
    • http://manilag.com/FileData/ckfinder/files/20210920_AAB7286273F55BC5.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16140e4fb21a91---guzivatelenikifub.pdfIn PDF document text
    • https://www.potravinyav21.cz/ckfinder/userfiles/files/pewatupoxo.pdfIn PDF document text
    • http://windmill-bv.com/userfiles/files/34078946450.pdfIn PDF document text
    • http://theheavent.com/userfiles/files/gudaduxekena.pdfIn PDF document text
    • https://blogsma.com/files/bajomotaruvukerowete.pdfIn PDF document text
    • http://neogmbh.de/www/sites/default/files/userfiles/file/40983955310.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/keruluxiborewejupuw.pdfIn PDF document text
    • http://mcserpenti.com/userfiles/file/12530178017.pdfIn PDF document text
    • https://exclusivelimoservice.com/ckfinder/userfiles/files/sepowasisa.pdfIn PDF document text
    • http://duda-tech.pl/dudatech/upload/file/lepakukazosada.pdfIn PDF document text
    • https://valstybestarnyba.com/upckfinder/files/11971545465.pdfIn PDF document text
    • https://vinadesigndanang.vn/uploads/image/files/58518411117.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=phrasal+verbs+fce+exercises+pdfPDF link annotation
    • 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://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_off0000b3ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3CA 16112 bytes
SHA-256: 67113440bc47e27309cf2aa7c9a8274938fdc6b2f56d4e51295db84ac2ef1251
font_01_sfnt_off0000dc8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC8A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f4a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4A1 10704 bytes
SHA-256: 1529f431ff56713e3cd0a36f2dad44dfbd00a5c4f37fa5a1cd2f7c0476350af7