Malicious PDF — malware analysis report

Static analysis result for SHA-256 23665d3f1a98ca19…

MALICIOUS

PDF

78.8 KB Created: 2021-09-08 21:31:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 144ed5dfa7c1f3c51f27190ee28ff4ee SHA-1: 3b489ec14bacf21014953ac55941263e337c94ce SHA-256: 23665d3f1a98ca1947c071858a6234a96faedca060ac5cb34d096a87fd2bc82b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of numerous external URIs and a PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests the document is part of a link farm designed to manipulate search engine results or distribute malicious content. The document body was unreadable, but the heuristics strongly indicate a phishing or malicious content distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://giant-nano.com/app/webroot/userfiles/files/91530062206.pdf In PDF document text
    • http://northmarking.com/userfiles/files/97118998594.pdfIn PDF document text
    • http://poetische-malerei.de/web/editor/files/13917202143.pdfIn PDF document text
    • https://testpensija.bankai.lv/ckfinder/userfiles/files/45169626570.pdfIn PDF document text
    • http://almawred-sy.com/files/adminfiles/files/71123919690.pdfIn PDF document text
    • https://tonere.shop/app/webroot/files/userfiles/files/nabezisiwogadu.pdfIn PDF document text
    • http://www.hangmandigital.com/files/file/rarupo.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/f40451412ac1e5c2cc93bbaa7d36f97b/mipowafixesofaji.pdfIn PDF document text
    • https://uslugiinzynierskie.eu/eurostyl/photos/file/dujokiremiguzizumofufeji.pdfIn PDF document text
    • http://cjmfgx.morefriendship.com/upload/files/suneg.pdfIn PDF document text
    • https://fceresources.com/ckfinder/userfiles/files/8894941343.pdfIn PDF document text
    • https://seltec.io/images/uploads/files/21652842748.pdfIn PDF document text
    • https://petandpuppies.com/userfiles/file/dozajosa.pdfIn PDF document text
    • http://gzky.cn/dubeite/ckfinder/userfiles/files/20210905_092531.pdfIn PDF document text
    • http://termocity.by/pics/files/mugik.pdfIn PDF document text
    • https://klubkanine.com/home/klub/public_html/ckfinder/userfiles/files/77615283402.pdfIn PDF document text
    • http://jeanchapleau.com/userfiles/file/53929379687.pdfIn PDF document text
    • http://romovi.net/sgi_userfiles/userfiles/files/85091896154.pdfIn PDF document text
    • https://www.weldcor.ca/public/ckfinder/userfiles/files/jobedikunokumek.pdfIn PDF document text
    • http://helloslow.com/data/userfiles/files/xofuxokumajagegokuxexu.pdfIn PDF document text
    • http://vetsnab32.ru/userfiles/file/muvewusilewigipaworo.pdfIn PDF document text
    • http://cartonwrappingmachine.com/userfiles/file/vinodemotubukipakekotafad.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16131a5a6dc891---49117669285.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=psychomotor+domain+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_off0000cef5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEF5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e70c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE70C 10820 bytes
SHA-256: 9d92bd58e614ffb26a5a7124a96c500d29fd71c2f9dfb4fdf86b9b81f895bddd
font_02_sfnt_off0000ffd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFD5 18012 bytes
SHA-256: 81a9610bdb4aad7b94ec823f0c4c8a0249aecdc6a3329dca8dd72e2e734a7ef7