Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd5bb19c0cee3806…

MALICIOUS

PDF

83.3 KB Created: 2021-09-09 06:51:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ffb64fa14fedc6547958f723c0c9eb31 SHA-1: 645fb65dd1d26f48fafcaae19e94c7d578540173 SHA-256: cd5bb19c0cee380651dea7aa938396f09be0bc8f6c7df138a7fe2be5edaacd7f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to suspicious PDF files on various domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using disposable hosting for these links, common in phishing or malware distribution campaigns. While no scripts were explicitly extracted, the nature of the embedded URLs and the detection as a phishing trojan strongly suggest an intent to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://amdind.com/userfiles/file/nowaxumew.pdf In PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/lisekuridudoxulibepogaw.pdfIn PDF document text
    • http://sindikat777.ru/ckeditor/ckfinder/core/connector/php/uploads/files/42731321095.pdfIn PDF document text
    • http://himalayakebab.irafbrothers.com/shipinc/userfiles/files/zewezamokurakemovetaf.pdfIn PDF document text
    • http://smepil.com/ckeditor/userfiles/files/buxojori.pdfIn PDF document text
    • http://reopen911.info/media/file/selamavebajuvulosox.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161383178c8c6a---somubafafewigivisobif.pdfIn PDF document text
    • http://hotel-gerard-dalsace.com/upload/document/zufizezisugoj.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/70e22699e4c800c614328c8422ae9e0d/wujataduvasekebuze.pdfIn PDF document text
    • http://balalajka.nu/media/70296040540.pdfIn PDF document text
    • https://ww150007.linebot.net/upfile/files/20210906213752.pdfIn PDF document text
    • https://digireg.cn/upload/mowilezizoxilazot.pdfIn PDF document text
    • http://aapltd.net/userfiles/file/97498808173.pdfIn PDF document text
    • http://altronic.pl/!mag2011/userfiles/file/sukivin.pdfIn PDF document text
    • http://ceroki.com/image/files/39868183218.pdfIn PDF document text
    • http://cafesezony.ru/fck_editor_files/files/vabam.pdfIn PDF document text
    • http://sinoscaform.com/upload/ckimg/files/202109070628055016.pdfIn PDF document text
    • http://botaierpharm.com/upload/files/zovimotu.pdfIn PDF document text
    • https://talenthunt.biz/userfiles/file/33074669830.pdfIn PDF document text
    • http://timnhanhonline.com/upload/files/depuzilafim.pdfIn PDF document text
    • https://www.cosanuesa.com/componentes/editor/ckfinder/userfiles/files/13525985385.pdfIn PDF document text
    • http://pro-group.ru/userfiles/files/81720934380.pdfIn PDF document text
    • http://bassonconsulting.mc/userfiles/file/vumisabewofu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=watch+kingsman+2+onlinePDF 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_off0000dfe7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFE7 18348 bytes
SHA-256: 81ac1bb4d238e27e2c17fc2335bb783f3722bef6f907e87aae6de6353c6e243f
font_01_sfnt_off00010f20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F20 10780 bytes
SHA-256: 9b62cd0c5131a6a83217e816077eebbf51453b71a7e5b0dccf875e66b2ca12c2
font_02_sfnt_off000127e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1