Malicious PDF — malware analysis report

Static analysis result for SHA-256 efd3900226638f0f…

MALICIOUS

PDF

68.2 KB Created: 2021-09-25 00:22:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 3c9de905a35fa3eb819b4048aeea51f0 SHA-1: c4d30258d090a1ef1df2aec1f5141e965e2a279a SHA-256: efd3900226638f0fab7d8809253785ce2dc38a70992a4c63306155d159e14451
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous links, many pointing to compromised CMS uploads and disposable hosting, characteristic of a link farm used for phishing or malware distribution. The presence of multiple external URIs and link farm heuristics strongly suggests the document's purpose is to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://eltechma.com/zdjecia/fck/file/47605326695.pdf In PDF document text
    • https://anne-berger.de/sites/anne-berger.de/files/fkcfile/36978531498.pdfIn PDF document text
    • http://jandebruijn.com/uploadimages/files/71903698242.pdfIn PDF document text
    • http://autowassenindex.nl/images/uploads/jadum.pdfIn PDF document text
    • http://novafish.it/userfiles/files/pojamegekofonofuranot.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/j7dmbf2cmt7i8ajmonu4i42692/venawedepaxipel.pdfIn PDF document text
    • http://newbusan.net/FileData/ckfinder/files/20210909_667EEDAE4350418A.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee3a564ebc---jebukadelegebiponapobun.pdfIn PDF document text
    • http://projecthouse.bg/uploads/CKfinder/files/biwijifun.pdfIn PDF document text
    • http://rsentco.com/upload/file/65625922733.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613e85e19e37f---83054109072.pdfIn PDF document text
    • http://kino-cosmik.ru/sadm_files/45111425079.pdfIn PDF document text
    • https://priscar.com/documents/files/50102233599.pdfIn PDF document text
    • http://rbc-bezorgdiensten.nl/upload/65872562637.pdfIn PDF document text
    • http://www.oomedia.com.tw/ckfinder/userfiles/files/33922646419.pdfIn PDF document text
    • http://ilyxrace.com/userfiles/files/demupado.pdfIn PDF document text
    • https://cheeselicious.net/UserFiles/file/fixekezipa.pdfIn PDF document text
    • https://biorenta.lt/ckfinder/userfiles/files/33482929924.pdfIn PDF document text
    • http://www.darvidproperty.com/news/file/sisitaruwon.pdfIn PDF document text
    • https://cornerstonelaw.eu/userfiles/file/31331284928.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210916170401.pdfIn PDF document text
    • https://artesapanaderia.xyz/aym_image/files/22556274326.pdfIn PDF document text
    • https://webmakler.org/userfiles/file/85503695274.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=lick+runner+apkPDF 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_off0000ad55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD55 15508 bytes
SHA-256: f95bc05187293aa71e6455a9e15bade97945dd222f875f3174581c0562132a82
font_01_sfnt_off0000d3e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3E8 10084 bytes
SHA-256: 74d6971806ec97d77d30862066bb1b6c3331982d61a9283c6768f6869c775271
font_02_sfnt_off0000ea6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA6F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1