Malicious PDF — malware analysis report

Static analysis result for SHA-256 0385a4143d8fb76b…

MALICIOUS

PDF

71.4 KB Created: 2021-09-15 18:47:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 86aaca92db7cd9a4c9e00647cef86686 SHA-1: 26c701dd7491e395c8e8ba467ec69737fa495127 SHA-256: 0385a4143d8fb76b752c310cf2d9fe90159ea6720b4133fc2ba4738fb710243e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it's a link farm on disposable hosting. The PDF contains numerous external URIs pointing to various domains, suggesting an attempt to redirect users to malicious websites. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly indicate a phishing or malware distribution vector, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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.
  • 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://medvor.ru/uplcv?utm_term=sharingan+live+wallpaper+free+download PDF link annotation
    • https://intervalhousehamilton.org/ckfinder/userfiles/files/xabewanonaxikopewoneku.pdfIn PDF document text
    • http://ohmytour.kr/FileData/ckfinder/files/20210910_A40652A744EB706D.pdfIn PDF document text
    • http://bighost.vn/uploads/userfiles/file/jalojodamubomigu.pdfIn PDF document text
    • http://articolo17.it/siti/usr/foto/files/nexewojutavivaz.pdfIn PDF document text
    • https://www.gpaci.org.br/cms/ckfinder/userfiles/files/woxajomotukinokev.pdfIn PDF document text
    • http://www.saveurspoitoucharentes.com/admin/ckfinder/userfiles/files/kawidakinowoguve.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/15113255615.pdfIn PDF document text
    • http://ventima.ru/userfiles/file/xopixokinegukazef.pdfIn PDF document text
    • http://eraldocomo.it/userfiles/files/suxebuzujulubinevij.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/16137485e4d67e---mesotajivugo.pdfIn PDF document text
    • http://elai.kz/upload/2021/09files/210913124940634993s4ju3.pdfIn PDF document text
    • https://thehouseconcert.com/ckfinder/userfiles/files/87298835543.pdfIn PDF document text
    • http://carrozzeriabosini.net/userfiles/files/84248101554.pdfIn PDF document text
    • https://anitt.in/ckfinder/userfiles/files/tevewulepi.pdfIn PDF document text
    • https://maturana.cl/upload/file/42056072015.pdfIn PDF document text
    • http://zzquansu.cn/d/files/22180983658.pdfIn PDF document text
    • http://tbeaindia.com/userfiles/file/jilebum.pdfIn PDF document text
    • http://vinag7furniture.com/app/webroot/files/editor_upload/files/malirejosodujaxaku.pdfIn PDF document text
    • http://bibliotekaszamocin.pl/img/upload/files/83997095984.pdfIn PDF document text
    • https://suacuachuyennghiep.com/uploads/files/23797878169.pdfIn PDF document text
    • https://shivajigrihnirman.com/singhania/downloads/file/wefifetixe.pdfIn PDF document text
    • 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_off0000b09b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB09B 10736 bytes
SHA-256: af9041524fa5cf145d850e207587044f3eabb69fc7015059d827b0cfcea5c8b7
font_01_sfnt_off0000c905.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC905 18192 bytes
SHA-256: 871947162fc9c99642a0c0a3056efc37089985a3f4bc9de8abf754f5d1df5ac4
font_02_sfnt_off0000f80a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF80A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1