Malicious PDF — malware analysis report

Static analysis result for SHA-256 41c93524570dba0a…

MALICIOUS

PDF

69.8 KB Created: 2021-09-09 06:47:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: af36f0df085cf4e3083873784c0177a2 SHA-1: e0c250e6e449ddf879d0045dab2939531fa1f8ba SHA-256: 41c93524570dba0a6a3757cf77efe0fddc82bb0a7385ab6698abf51e9e9def86
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs and is flagged as a link farm on disposable hosting, suggesting it's used to redirect users to malicious sites. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://somogyplusz.hu/files/dipalejomodezasamigikajix.pdf In PDF document text
    • http://dezis.ru/uploads/files/36389741293.pdfIn PDF document text
    • https://loyallcanada.com/editor_files/file/tumokazexipiwazabefejex.pdfIn PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/tiwez.pdfIn PDF document text
    • http://prakseologia.eu/userfiles/file/mijodimobefejux.pdfIn PDF document text
    • http://svenskafik.se/uploads/fckeditor/file/lekawuder.pdfIn PDF document text
    • https://swaarm.de/app/webroot/upload/files/narevob.pdfIn PDF document text
    • http://acelybio.com/upload/files/viduborafojedogiwazafab.pdfIn PDF document text
    • http://ip-malkov.ru/uploads/files/natifiv.pdfIn PDF document text
    • https://emilline.dk/ckfinder/userfiles/files/10561756343.pdfIn PDF document text
    • https://royal-art.pl/uploads/userfiles/files/nigifikapisufawisajad.pdfIn PDF document text
    • https://www.premiumtrade.ro/ckfinder/userfiles/files/15322563202.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16133b1a26f494---86805865554.pdfIn PDF document text
    • http://cmrivestimenti.com/userfiles/files/gonometusan.pdfIn PDF document text
    • https://dascalita.ro/app/webroot/files/userfiles/files/55161418834.pdfIn PDF document text
    • http://agriturismolionsfarm.it/userfiles/files/71819054374.pdfIn PDF document text
    • https://hsdinstruments.nl/uploads/files/vopotupijivun.pdfIn PDF document text
    • http://househouse.it/userfiles/files/gaxagamenisajapametid.pdfIn PDF document text
    • https://ceramicasvillaflor.cl/UserFiles/File/tisevisaxozadupigozufasit.pdfIn PDF document text
    • http://cortabellanews.com/userimages/lubabaxibomi.pdfIn PDF document text
    • http://baovephuongtroi.com/vietkiendo/upload/file/27664384168.pdfIn PDF document text
    • https://electrodomesticaruano.com/images/ckfinder/files/kigarovuwon.pdfIn PDF document text
    • http://nensi.si/upload/file/61427344536.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/vi4395hbpcesi5f634ci5h4tuf/zuviliju.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=sim+hack+apkPDF 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_off0000b217.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB217 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA2E 10040 bytes
SHA-256: 03074889489d2fd355ce2d706ec9bae5858429e578c68989566ce7f495c0808b
font_02_sfnt_off0000e073.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE073 16264 bytes
SHA-256: 0a188b8b7b64d59f1c5ad56f2ed4f0d274f6014e5551b8e3ac2193d4a2435546