Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8331b362ee45fcc…

MALICIOUS

PDF

86.9 KB Created: 2021-09-09 17:11:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 374084681265257c69ed313ad9a1fff7 SHA-1: 8d836ba40ed737a5a84ce4b0950137f49e5f5001 SHA-256: c8331b362ee45fcc749d132c3a7ee6a04ab8e22d1b3143210c62eab55aa69be4
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 domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The embedded JavaScript is a common technique for initiating malicious actions within PDF documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://kibbkw.com/uploads/files/9276427430.pdf In PDF document text
    • http://llux.vn/uploads/files/65019795719.pdfIn PDF document text
    • http://svx.su/ffile/file/jijamijewotusu.pdfIn PDF document text
    • https://windsbs.biz/files/file/13417909427.pdfIn PDF document text
    • http://studiodrago.eu/userfiles/files/59240307861.pdfIn PDF document text
    • http://sartor.ru/upload/files/sefosulijugo.pdfIn PDF document text
    • https://at1apigroup3.com/contents/files/nijusobifaneduwata.pdfIn PDF document text
    • https://dom4m.lv/userfiles/files/53078938896.pdfIn PDF document text
    • https://ctcitsupport.com/media/files/84358340403.pdfIn PDF document text
    • https://balaji-technology.com/userfiles/file/koputibipaxo.pdfIn PDF document text
    • https://mimpidia2.com/contents/files/83780229486.pdfIn PDF document text
    • http://krupongs.com/images/file/zababefekoxikotazozamaleg.pdfIn PDF document text
    • https://sangolongphuong.vn/longphuong/news/files/52840119829.pdfIn PDF document text
    • http://studiopiergentili.it/userfiles/files/muwoborenufuwuriparedoro.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/56a8770a2b54e0278f0a0f5c025d7f39/41881480228.pdfIn PDF document text
    • https://edenestates.com/ckfinder/userfiles/files/vapaloruguwaporebu.pdfIn PDF document text
    • http://fratellilongoni.com/userfiles/files/40846158163.pdfIn PDF document text
    • https://minlinart.com/archive/upload/files/puvunomuteja.pdfIn PDF document text
    • http://baovecongtruong.com/upload/files/73269683023.pdfIn PDF document text
    • http://downtowncincyhotels.com/core_degree/admin/images/cms_imagesfiles/90873106607.pdfIn PDF document text
    • https://www.agencesramos.com/ckfinder/userfiles/files/56075234349.pdfIn PDF document text
    • https://keiba-like.biz/js/ckfinder/userfiles/files/83554485459.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137ffbf00bfb---dexaxusatesanoxinutipi.pdfIn PDF document text
    • http://architettogherardi.eu/userfiles/files/80700006314.pdfIn PDF document text
    • http://theffirm.com/userfiles/file/jufewefikomideduxod.pdfIn PDF document text
    • http://topbondtape.com/uploadss/file/30906829778.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=afk+immortal+legend+of+heroesPDF 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_off0000e84d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE84D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001005f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1005F 20052 bytes
SHA-256: d58d7994b0f8f4404ff723d0af9b953ecdafd2138a9e6b01f4de1f7a8f810d62
font_02_sfnt_off000134a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134A0 10876 bytes
SHA-256: a7e334dfafc8f18fb841d3e2fbe82838e510572b1e0e34a2691457c44cdabc55