Malicious PDF — malware analysis report

Static analysis result for SHA-256 b13801585a3a90c6…

MALICIOUS

PDF

88.9 KB Created: 2021-09-20 15:12:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a4ca1467dc96f51414709cb0dcb139de SHA-1: cfaf37d8c9928374a17f27f817462a17dd9df4d6 SHA-256: b13801585a3a90c63560e01e3f664d969cd5a96907017002b4ad1eba674cec4e
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

This PDF sample was flagged by ML classifiers and ClamAV as malicious. It contains embedded JavaScript, indicating an attempt to execute code upon opening. The PDF also functions as a link farm, hosting numerous links to other PDF files on disposable domains, suggesting a distribution or phishing campaign. The presence of embedded JavaScript and the link farm structure strongly suggest the intent to download and execute a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://fo-prefectures.com/pages/files/75702655174.pdf In PDF document text
    • http://bananamusic.tw/uploads/files/202109022015599525.pdfIn PDF document text
    • https://onwater.my/uploads/file/xolodoperubaban.pdfIn PDF document text
    • http://finpacecuador.com/userfiles/file/42932203731.pdfIn PDF document text
    • http://orderkiwicafe.com/uploads/files/jemasitizalejarobarema.pdfIn PDF document text
    • http://kingsap.com/file_media/file_image/file/53159971349.pdfIn PDF document text
    • http://www.phsdcenter.com/temp/js/ckfinder/userfiles/files/66548761811.pdfIn PDF document text
    • http://joomlacode.org/fckeditor/editor/filemanager/img.php?file=file/28042240913.pdfIn PDF document text
    • https://andymullinscommercial.com/home/andy/public_html/ckfinder/userfiles/files/59476081026.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/q6bj8c25ss8o1r4bcn9il4bdnr/viposaxetigururapego.pdfIn PDF document text
    • https://zoorichi.com/temp/fckeditor/file/namidevisubukixulo.pdfIn PDF document text
    • https://greenfuturevietnam.com/Upload/files/54018611482.pdfIn PDF document text
    • http://sllight.ru/design/img/upload/file/61945072138.pdfIn PDF document text
    • http://amunt.madteam.net/ckfinder/userfiles/files/taxutonodesakikawajumenaz.pdfIn PDF document text
    • https://equalland.com/uploads/File/94010558783.pdfIn PDF document text
    • http://otevrel.eu/ckfinder/userfiles/files/68496086445.pdfIn PDF document text
    • https://www.bmo-agencement.fr/ckfinder/userfiles/files/pugilininipisuvaraxorep.pdfIn PDF document text
    • http://0-50.ru/userfiles/file/nosexixej.pdfIn PDF document text
    • http://platypusspot.org/uploads/ckfinder/userfiles/files/68909050163.pdfIn PDF document text
    • https://estudiowebcolombia.com/ckfinder/userfiles/files/91990665175.pdfIn PDF document text
    • http://musiclivemarsala.com/userfiles/files/68355124376.pdfIn PDF document text
    • https://bnbtravels.com/ckfinder/userfiles/files/zavukapirotajoxeko.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161435f91d4562---91433439111.pdfIn PDF document text
    • http://mp-journal.com/media/file/gebebiraz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=gulliver%27s+travels+questions+and+answers+pdfPDF 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_off0000f4b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B8 18168 bytes
SHA-256: 579e7195e45864895e992a92409bafc417176f29f754902bfe43edd1c5680dc7
font_01_sfnt_off00012418.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12418 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013c2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C2F 10964 bytes
SHA-256: ab1a428639c8e2ad2dd28a52962f41a8ed41038cd5fc4eb91ece664e20094ca7