Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4bf755dc00273a1…

MALICIOUS

PDF

84.0 KB Created: 2021-09-14 07:30:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d913bd2566998944ac9de96f00e91272 SHA-1: 4f6d18ca879fbae7494b77acb9b21832d8768076 SHA-256: e4bf755dc00273a1003f3511e5a54c27508575d83e69c8c7ae45fa3e0ab215a6
126 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV. It functions as a link farm, containing numerous links to external PDF files hosted on various domains, indicating a potential phishing or malware distribution scheme. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically flags this behavior, suggesting an attempt to obscure the true malicious intent through a large number of low-reputation domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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 http://euroteam.vn/ckfinder/userfiles/files/55093884002.pdf In PDF document text
    • https://spirit-legend-enterprises.com/webroot/editor-uploads/files/22405508269.pdfIn PDF document text
    • http://abwrichmond.com/uploads/files/mofozivovogidopebidi.pdfIn PDF document text
    • http://rollfactorytogo.com/uploads/files/kasunafukemirabewe.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/99810148723.pdfIn PDF document text
    • http://dominoliberec.eu/images/file/files/8957247229.pdfIn PDF document text
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/32603500273.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130457df012c---fiwuvitijinezavewubatiz.pdfIn PDF document text
    • http://frankifoto.com/uploads/pages/files/lewebalemuri.pdfIn PDF document text
    • http://aleshashop.net/uploaded_files/userfiles/files/42430210458.pdfIn PDF document text
    • http://vagyonvedelemszolnok.hu/admin/fck_upload/file/59068612471.pdfIn PDF document text
    • http://caycanh.vn/images/fck/file/81507357210.pdfIn PDF document text
    • http://ck-kutnahora.cz/gais/image/file/40770808095.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613eb37d8e3b4---56065986104.pdfIn PDF document text
    • http://tbeaindia.com/userfiles/file/pidibezip.pdfIn PDF document text
    • http://marasintl.com/public/ckfinderuploads/files/luvetetexafigagonadiw.pdfIn PDF document text
    • http://lotusromeo.fr/app/webroot/files/userfiles/files/fiwakifejixofatij.pdfIn PDF document text
    • https://vanchuyenduongsat.vn/upload/files/metekegerokiva.pdfIn PDF document text
    • http://clubselectionvoyages.net/images/file/10958974589.pdfIn PDF document text
    • http://mos-craciun-inchiriere.ro/fckfiles/file/bowutobetadikenevebamiw.pdfIn PDF document text
    • http://janaturismointegrato.com/uploads/file/dotefuponosemigig.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/45203872838.pdfIn PDF document text
    • https://bushregenerators.com/userfiles/files/42715853635.pdfIn PDF document text
    • http://cuacuongiare.vn/upload/files/safopirewafoma.pdfIn PDF document text
    • http://pivotal-technologies.com/userfiles/file/bazuravo.pdfIn PDF document text
    • http://arredamentoambienti.it/img/file/gigebula.pdfIn PDF document text
    • http://ottomaniantextile.com/userfiles/file/jiweduv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=yuval+noah+harari+knjige+pdfPDF 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_off0000dfa5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFA5 10880 bytes
SHA-256: 584554d9d3deee22deb8cf5949dbaac52f0689231a460caa5b58a4a081dff1ef
font_01_sfnt_off0000f865.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF865 18888 bytes
SHA-256: 8a68582be75ac766da4872c6f82913a7bdcb3e3e4bbcfea0004e612b7801eb2b
font_02_sfnt_off00012976.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12976 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1