Malicious PDF — malware analysis report

Static analysis result for SHA-256 e158b23344daa8d9…

MALICIOUS

PDF

80.2 KB Created: 2021-09-15 19:55:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: cbf5a184abd6050b7404f972864a3586 SHA-1: 0001873dbfbc5c334ee42bc8e6caa99d46f75890 SHA-256: e158b23344daa8d9f6a930b5613e730a6afa1fe1c672ea11ba21e7e1216a5158
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to external PDF files, suggesting it functions as a link farm or a distribution point for further malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a pattern of using disposable hosting for link aggregation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 http://linkipt.com/_UploadEditor/files/zutizagifosopenodofizik.pdf In PDF document text
    • https://prevodi-plovdiv.com/userfiles/file/17962422122.pdfIn PDF document text
    • http://golfproradost.cz/webpagebuilder/ckfinder/userfiles/files/favusax.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/7057fb3972931a31fe7a954e9bf02631/pupibixamivimub.pdfIn PDF document text
    • http://www.uc-kushiro.net/images/library/File/gotuf.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132088d204b5---feketagidatowoz.pdfIn PDF document text
    • http://tuanlongland.com/upload/files/35138968816.pdfIn PDF document text
    • http://araonline.hu/uploads/file/13879585797.pdfIn PDF document text
    • http://placidlakes.com/larpm/uploads/file/vizanaliregafur.pdfIn PDF document text
    • http://unitec-egypt.net/userfiles/file/86918590641.pdfIn PDF document text
    • https://leganordavigliana.com/uploads/file/17594851320.pdfIn PDF document text
    • http://www.juthamasclinic.com/upload/finder/files/54526170203.pdfIn PDF document text
    • https://doublehair.center/upload/ckfinder/files/xikanarap.pdfIn PDF document text
    • https://kaptenhoki.com/contents/files/wewikodidorubon.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/8013267156.pdfIn PDF document text
    • https://aymexco.ro/ckfinder/userfiles/files/morawi.pdfIn PDF document text
    • http://ambvetfanini.eu/userfiles/files/witofopimiradenemo.pdfIn PDF document text
    • https://johanbjerke.se/userfiles/file/3059209899.pdfIn PDF document text
    • https://giolog.biz/images/bulk_images/files/fugifarewos.pdfIn PDF document text
    • https://ardiinerkh.mn/uploads/userfiles/files/3747347366.pdfIn PDF document text
    • http://cancunday.com/travela/img/files/zatoturuxupuwa.pdfIn PDF document text
    • https://santehsevast.ru/userfiles/files/riluxojotadupavopodagow.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=fixing+gps+on+androidPDF 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_off0000d304.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD304 18708 bytes
SHA-256: fb90770a6bffbbfb24f40f70153e953d78def5cf88fecfe08b1ca80dc3dcd2f4
font_01_sfnt_off00010417.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10417 10368 bytes
SHA-256: 0c1d40907beed275d1d51fae1f7a5da0abff81563081940c4532f0d847155eda
font_02_sfnt_off00011b5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B5F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1