Malicious PDF — malware analysis report

Static analysis result for SHA-256 eca134a8158c2c19…

MALICIOUS

PDF

83.4 KB Created: 2021-09-24 00:06:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b4608e315417caf6b116c61aac142f9e SHA-1: f2aec5bbe186315a9c6dbd78e61fe31881beba55 SHA-256: eca134a8158c2c192f177459dd6e63abf6abaf54317b5a72f73ade185495cf18
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to potentially malicious PDF files. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a tactic to obscure the true destination by using many distinct, low-reputation hosts. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to deliver a phishing lure or download a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://drhuanghair.com/uploads/files/202109150706273633.pdf In PDF document text
    • http://1night2day.com/ckupload/files/fujoxevo.pdfIn PDF document text
    • https://lotte-ppta.net/beta/assets/file/46874305688.pdfIn PDF document text
    • http://eskuvotoszkanaban.hu/editor_up/nawipamotogug.pdfIn PDF document text
    • http://savoie-outils-coupants.com/ckfinder/userfiles/files/92577198103.pdfIn PDF document text
    • http://gold-carsales.com/js/upload/files/73670141445.pdfIn PDF document text
    • https://shoppe.everybodyisnotdoingit.org/gift/userfiles/files/nobur.pdfIn PDF document text
    • https://associazionebriciole.it/public/file/11927808857.pdfIn PDF document text
    • https://cemb.ca/upload/editor/file/57702369278.pdfIn PDF document text
    • http://china-zub.ru/userfiles/file/40728334951.pdfIn PDF document text
    • https://8foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/8370418933.pdfIn PDF document text
    • https://quatden.vn/webroot/img/files/56261301570.pdfIn PDF document text
    • http://wjvanderheidedienstverlening.nl/uploads/file/nobabugubebomi.pdfIn PDF document text
    • https://sklepbonus.eu/userfiles/file/rorarinonapuxup.pdfIn PDF document text
    • http://bkdesign.ee/userfiles/file/fibor.pdfIn PDF document text
    • http://novichiha.ru/pic/file/50079866187.pdfIn PDF document text
    • http://e68momo.com/shopadmin/upload/files/35428387637.pdfIn PDF document text
    • http://german-ex.com/images/blog/file/nuboso.pdfIn PDF document text
    • http://eqletstalk.com/uploads/files/202109151454029532.pdfIn PDF document text
    • https://kibledergisi.net/resimler/files/14538988806.pdfIn PDF document text
    • http://futimisdev.com/userfiles/file/vutejabalipixonuxakezaril.pdfIn PDF document text
    • http://novehorizonty.sk/userfiles/file/palefu.pdfIn PDF document text
    • http://modaxch.com/userfiles/files/70203931397.pdfIn PDF document text
    • http://nonstopsushi.com/uploads/files/92205696468.pdfIn PDF document text
    • http://kaitosushisb.com/uploads/files/91474272516.pdfIn PDF document text
    • http://trufeel.com/ckeditor/ckfinder/uploadfile/files/14732249743.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=download+inshot+no+watermarkPDF 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_off0000e20a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE20A 10692 bytes
SHA-256: 2eaa33354e26410cc996c6093cd64bddc2bff8d9b327238a4906ae4fc890d35e
font_01_sfnt_off0000fa63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011275.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11275 17288 bytes
SHA-256: f71ccdd7fcf673a4ed1f6e26e0e72c8cf4ca5458a78fb10e4badc347825387ee