Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4b1b31d902c68b5…

MALICIOUS

PDF

79.6 KB Created: 2021-09-14 08:28:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 6817a0324205a5437f10823effc07d91 SHA-1: cbe35f4505b4ce8405a8d0a1565538742b12005e SHA-256: e4b1b31d902c68b5e438bc9cc044ade9d83a5872bf39239054d4da21d84be6f2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs pointing to external domains, indicating a likely phishing or malware distribution scheme. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic suggests these URLs are part of a link farm designed to obscure the true malicious destination. No scripts were extracted, but the presence of many external links strongly suggests the PDF's purpose is to redirect the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://synerhu.ru/uplcv?utm_term=eberron+campaign+setting+pdf PDF link annotation
    • http://www.oalysa.cz/ckfinder/userfiles/files/94808266059.pdfIn PDF document text
    • http://daedukgs.com/admin/fckeditor/data/file/20210909071509.pdfIn PDF document text
    • http://newmob.it/userfiles/files/jikan.pdfIn PDF document text
    • http://cuathepvangohaiduong.com/images/ckeditor/files/1266150430.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1613db9cf96acf---76026633738.pdfIn PDF document text
    • http://weiddy.com/uploads/files/202109121502173311.pdfIn PDF document text
    • https://sofupingame.com/calisma2/files/uploads/88239231461.pdfIn PDF document text
    • https://isagrinio.gr/userfiles/jolafakowonupajesoneb.pdfIn PDF document text
    • http://orchid-daikanyama.com/userfiles/file/lofubud.pdfIn PDF document text
    • https://ctners.com/ckfinder/userfiles/files/18141692261.pdfIn PDF document text
    • http://backkwang.com/userData/board/file/miwamovovesuxose.pdfIn PDF document text
    • http://nincity.de/inline/file/54802317348.pdfIn PDF document text
    • https://royal-art.pl/uploads/userfiles/files/172236022.pdfIn PDF document text
    • http://www.tecnobor.com/ckfinder/userfiles/files/sitajijenogosodusefo.pdfIn PDF document text
    • http://pereplanirovkaoblast.ru/pict/file/nugarigusolawuxarer.pdfIn PDF document text
    • http://rotarycochinharbour.org/ci/userfiles/files/87623800109.pdfIn PDF document text
    • http://www.pes.edu.mn/ckfinder/userfiles/files/pazakivul.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/qg8rparul6i4a7291s393n8isr/61595246128.pdfIn PDF document text
    • http://asupuro.com/upload/save_image/files/jenerobogafu.pdfIn PDF document text
    • https://autonoleggioassereto.com/file/65218075621.pdfIn PDF document text
    • https://editora-arara-azul.com.br/site/admin/ckfinder/userfiles/files/mesodalox.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_off0000d2ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2EF 11040 bytes
SHA-256: 81496ab75909eeff2eb73d5d673a9c3bd2f364bd60ff290624633a47040cb4a1
font_01_sfnt_off0000ec34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC34 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010446.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10446 17336 bytes
SHA-256: 7d36886828f72ffb121ae2ff5b7695d2cdb4fff746e6989f213add074a22a987