Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ea31823ecc8840d…

MALICIOUS

PDF

79.1 KB Created: 2021-10-08 12:50:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 9f5a0b9798d90f403e2293c64cf4dec6 SHA-1: 9ef516d6820a703f41c840e7353c5a6183f5360f SHA-256: 4ea31823ecc8840dc0da5c37528c44d9707dbf1ae8334b071680e50452068f06
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous embedded URLs pointing to external PDF files, suggesting a link farm or redirection mechanism. The presence of a URL with a 'utm_term' parameter further supports a phishing or malicious redirection scenario.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://ketchas.ru/uplcv?utm_term=12+quarts+is+equal+to+how+many+gallons PDF link annotation
    • http://geo-equipe.it/userfiles/files/69841363175.pdfIn PDF document text
    • http://hanilkwanla.com/uploads/files/kiveti.pdfIn PDF document text
    • http://kroonzuivel.nl/ckfinder/userfiles/files/59402529623.pdfIn PDF document text
    • https://szabolcsipeter.com/userfiles/file/82739682857.pdfIn PDF document text
    • http://colegiosantarosa.com/uploads/imagem/file/1100469977.pdfIn PDF document text
    • http://kaztelcom.kz/ckfinder/userfiles/files/taruganemilufumunetisilo.pdfIn PDF document text
    • http://davidhammerstein.org/userfiles/file/99991054842.pdfIn PDF document text
    • http://napiarsaigh.com/images/1873914294.pdfIn PDF document text
    • http://shinaval.ru/userfiles/file/rapipewapofor.pdfIn PDF document text
    • http://marinapogon.pl/upload/file/boxobafanigo.pdfIn PDF document text
    • http://longruiglass.com/ckfinder/userfiles/files/20210914_121222.pdfIn PDF document text
    • http://mini-garden.ru/userfiles/file/bawofatuwi.pdfIn PDF document text
    • http://autolubitel-irk.ru/userfiles/file/kitijukuvazojejixa.pdfIn PDF document text
    • https://peterdegendt.be/file/xexufabusosomulote.pdfIn PDF document text
    • http://ljjxmining.com/uploadfile/file///2021092720452572.pdfIn PDF document text
    • https://horkolas-gatlas.hu/ufiles/file/tijepovewofovowemome.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/sidapuvajatumerotoziv.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/301e14075187222f0e3e8f3aa66278de/18132366536.pdfIn PDF document text
    • https://aglogistics-bo.net/userfiles/file/bedaruravatogele.pdfIn PDF document text
    • http://albergocavour.com/userfiles/files/1378749100.pdfIn PDF document text
    • http://ginzaramen.us/uploads/files/34037386713.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://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_off0000d0ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e906.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE906 11076 bytes
SHA-256: 76dc80957f440519ef3a8ed36981f7f65b51d1710bcd18756461109dfba97f6b
font_02_sfnt_off00010282.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10282 17412 bytes
SHA-256: 0076380ddedafae509db1e2a8b907f726d11f7d359ef3991e8077fdb1f5f4bf4