Malicious PDF — malware analysis report

Static analysis result for SHA-256 85e4f465a0bdff1e…

MALICIOUS

PDF

81.5 KB Created: 2021-09-18 19:55:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: ba7e11439b12a7c73216dc4d90c875b0 SHA-1: 213e3cd1d176603f0716bb2b3e3de2dd2f819305 SHA-256: 85e4f465a0bdff1e8a6f2fb796009fc9768f36cd8b07a5b229507cccb96f1e73
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code within documents. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and the numerous extracted URLs suggest an attempt to redirect users to potentially malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://gsm.company/ckfinder/userfiles/files/30593430732.pdf In PDF document text
    • http://proclima-membranes.ru/userfiles/file/gavuwojove.pdfIn PDF document text
    • http://romangruszecki.com/uploaded/file/59581833589.pdfIn PDF document text
    • http://atmaircenter.com/lb/userfiles/files/79356603048.pdfIn PDF document text
    • https://vnnc.vn/img-hdmedia/files/30114073743.pdfIn PDF document text
    • http://heathrowairporttaxi.website/userfiles/file/digonokasafujigefi.pdfIn PDF document text
    • http://quetthe.com/upload/files/99397641055.pdfIn PDF document text
    • http://prtourusa.com/FileData/ckfinder/files/20210916_7E15B571AB045AC6.pdfIn PDF document text
    • http://bhartiyambeohari.in/userfiles/file/nebunuxadiwunado.pdfIn PDF document text
    • http://volkshilfe-ktn.at/images/content/files/jefajutuvuwapodizirojaga.pdfIn PDF document text
    • http://www.miyadenthai.com/image/upload/File/4344302802.pdfIn PDF document text
    • http://www.520amis.com/upload/files/wifojeviwirutezipajupi.pdfIn PDF document text
    • http://szpitalstrzelin.pl/userfiles/files/42215853205.pdfIn PDF document text
    • http://chipgene.com/image/files/20210910_021723.pdfIn PDF document text
    • http://tantex.org/tantex/tantexuserfiles/file/zajinipawebev.pdfIn PDF document text
    • http://fcraregistration.com/UploadedData/file/20480501613.pdfIn PDF document text
    • https://www.profiemg.cz/upload/ck/files/bepigesoxalibivesazusirem.pdfIn PDF document text
    • https://gymlesgeants.com/upload/editor/file/7118732951.pdfIn PDF document text
    • http://world-spa-resorts.com/dok/nutabanufula.pdfIn PDF document text
    • https://vsetinrally.cz/userfiles/file/jiwitoxudazujibo.pdfIn PDF document text
    • http://hamdannepal.com/userfiles/file/kavotojazepuje.pdfIn PDF document text
    • http://samtle.net/ckupload/files/47638306709.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/marurinipesoramu.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614138bd837d7---wizonuvibilaki.pdfIn PDF document text
    • http://daiduongmetal.com/uploads/ckfinder/files/ziwowa.pdfIn PDF document text
    • http://evergreendentistryva.com/app/webroot/js/ckfinder/userfiles/files/ludegimodejikedufamepewi.pdfIn PDF document text
    • http://leicesterbiketec.com/userfiles/file/41064445872.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+check+how+much+screen+time+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_off0000dbae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBAE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C0 16972 bytes
SHA-256: 1c4fc86ed4f9d641f2fd2cfad9332612069e58df68c678daf8fa63b3171f449c
font_02_sfnt_off00011f59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F59 10860 bytes
SHA-256: b3dd8e0e05056ff540d54f01cacf7a9e0384f8ae4f64c01892d8333f266073a0