Malicious PDF — malware analysis report

Static analysis result for SHA-256 dbf4a470c721702d…

MALICIOUS

PDF

80.2 KB Created: 2021-09-15 18:12:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: deed6d937ddf79837e42880b9913b966 SHA-1: 45c9e5b576651e1391ea99cf640467e8b9186ded SHA-256: dbf4a470c721702d0aa500a4d14648a338bf5f4133321f62930a9b9a4c28846c
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 disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to create a link farm for SEO purposes, likely to obscure the true malicious intent. The ML classifier and ClamAV detection strongly suggest malicious activity, with the embedded JavaScript likely responsible for initiating the download of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://fitnessklub-impuls.pl/uploads/assets/file/36833949702.pdf In PDF document text
    • https://arab-hams.com/Ups/files/fabosijakuzinuzivov.pdfIn PDF document text
    • http://networkinglikepro.com/ckfinder/userfiles/files/bewuzalopemuzosa.pdfIn PDF document text
    • http://cellesekorea.com/ckupload/files/33950953819.pdfIn PDF document text
    • http://bctlorraine.org/userfiles/file/pusexawufuvulelabadijotut.pdfIn PDF document text
    • http://abwingsbuffalo.com/uploads/files/44722775845.pdfIn PDF document text
    • http://www.colormotion.cz/UserFiles/file/rutanerexu.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/somupugojogizefovasakizaz.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/161398d2949e58---48211091708.pdfIn PDF document text
    • http://tehnicgaz.eu/files/file/dilodewunavesifufuvek.pdfIn PDF document text
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/9ec3d6a8d71242368c40fee001874359/pozugikejovapuvonap.pdfIn PDF document text
    • http://gospel-pour-100-voix.com/fichiers/newsletter/file/79117813257.pdfIn PDF document text
    • http://ecilingirler.com/resimler/files/rupexudimo.pdfIn PDF document text
    • http://lynhuagiasi.com/Images_upload/files/33684159406.pdfIn PDF document text
    • http://feuerwehrobrigheim.de/upload/files/1816310806.pdfIn PDF document text
    • https://beta.nhatthiengroup.com/files/uploaded/files/9928218353.pdfIn PDF document text
    • http://avesta-hmora.boj.se/uploads/userfiles/files/xuzanom.pdfIn PDF document text
    • https://enilubricantvn.hoakhanh.vn/uploads/image/files/52679332716.pdfIn PDF document text
    • http://autostyle-japan.com/js/upload/files/zigozezovagoxam.pdfIn PDF document text
    • https://cosanuesa.com/componentes/editor/ckfinder/userfiles/files/94365958099.pdfIn PDF document text
    • http://louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/70081928983.pdfIn PDF document text
    • http://fipjp.com/userfiles/file/48372565392.pdfIn PDF document text
    • http://tbff-bygg.se/img/files/jatubuvuxeberolifigilibat.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=justice+league+subtitles+downloadPDF 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_off0000d597.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD597 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eda9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDA9 17304 bytes
SHA-256: 88ed03d7b7b295753c025e9d9189e3ba02f8c8a5bf715b1a2df9ac0894949ab5
font_02_sfnt_off00011a4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A4E 10760 bytes
SHA-256: 14c8239296cfd9ccf66d164a0a8a1d4a7039dc5a26600df1e68c64ddb4db1acc