Malicious PDF — malware analysis report

Static analysis result for SHA-256 25a640ba85bfe5de…

MALICIOUS

PDF

86.7 KB Created: 2021-09-24 09:01:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 7ce503713438fcd1b9e22d22e7d0af65 SHA-1: 27af79d2a0a545f78e453d64bf382be5914de74a SHA-256: 25a640ba85bfe5de24ea8d4f1e73c92ebbdcc1808551fe1865eebfd63e09e8af
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, indicating an attempt to redirect the user to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The presence of embedded JavaScript points to T1059.007, and the nature of the file suggests it was likely delivered as a Spearphishing Attachment (T1566.001).

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://daotao.cungthieunhidanang.vn/app/webroot/upload/files/22026403169.pdf In PDF document text
    • http://nut-shell.net/upload/files/duzugo.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161344beb8e19f---mikasufo.pdfIn PDF document text
    • http://zjleiou.com/images/upload/File/3464231392.pdfIn PDF document text
    • http://infiniti.e-library.tw/uploads/files/20186730819.pdfIn PDF document text
    • https://alhasooncorp.com/Files/files/kaveluz.pdfIn PDF document text
    • http://vswet.ru/f/dopilenajenelomebugizi.pdfIn PDF document text
    • http://bamboomfi.com/htdocs/cljr/data/files/jikajawob.pdfIn PDF document text
    • https://mimpishio1.com/contents/files/pusudasogilirurazaguj.pdfIn PDF document text
    • http://mudrberanova.cz/userfiles/file/37144079499.pdfIn PDF document text
    • http://montpellier-business-plan.eu/mbp/upload/images/images/upload/ckfinder/62367554952.pdfIn PDF document text
    • http://autoklej.pl/app/webroot/media/files/nabedadox.pdfIn PDF document text
    • http://sipzip.com/userfiles/file/41810540061.pdfIn PDF document text
    • https://skiclubraonbaccarat.fr/pdf/26680656999.pdfIn PDF document text
    • http://tongchangkj.com/uploadfile/file///2021092312544274.pdfIn PDF document text
    • https://vntdc.com/upload/fck/file/28477354525.pdfIn PDF document text
    • http://cuacuontoanthang.com/media/file/falazelupipubaxeredobobek.pdfIn PDF document text
    • https://subarini.ro/mm/file/32289284648.pdfIn PDF document text
    • https://quangcaowebsite.vn/uploads/files/50625237976.pdfIn PDF document text
    • http://nanchang.chinatupai.com/web/js/ckfinder/userfiles/files/53498394382.pdfIn PDF document text
    • https://svenjakretschmer.com/ckfinder/userfiles/files/89385174564.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/711124706ba4a9d3c79c639d2753f8e9/7797666641.pdfIn PDF document text
    • https://subded.org/userfiles/file/71243850549.pdfIn PDF document text
    • http://ozdermusavirlik.net/userfiles/file/93309738939.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=best+app+to+listen+music+online+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_off0000ed64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED64 18068 bytes
SHA-256: b00ef3667cd58fa2227498c3537a43e5644cb9c161cab2dd625426080f60751f
font_01_sfnt_off00011bdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BDB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000133f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133F2 10828 bytes
SHA-256: a4245f7ffd2086f8714aa7725723d71b8778094b2cf4e8faadfadbce86dff471