Malicious PDF — malware analysis report

Static analysis result for SHA-256 b808ac636352096f…

MALICIOUS

PDF

75.2 KB Created: 2021-09-25 03:09:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9b3257ab766a8008f0910b6110b890b8 SHA-1: 956e079ca45b899bf29727f86229cb8f8933bcd8 SHA-256: b808ac636352096f79e636170a12bc5c0103ddbc21bc80ad7cfaa31ae5e287ca
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a machine learning classifier and ClamAV, indicating malicious intent. It functions as a link farm with numerous embedded URLs pointing to potentially malicious or phishing sites, as evidenced by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://deycaterers.com/ckfinder/userfiles/files/94942609193.pdf In PDF document text
    • http://hoanhaochemical.com/uploads/files/18824371173.pdfIn PDF document text
    • https://autopsrus.aerovents.com/ckfinder/userfiles/files/kefusovejubevu.pdfIn PDF document text
    • http://yas-center.ru/userfiles/file/43173171891.pdfIn PDF document text
    • https://adikketiga.com/contents/files/jaxove.pdfIn PDF document text
    • http://pro-group.ru/userfiles/files/vakefobo.pdfIn PDF document text
    • http://faceconnects.com/ci/userfiles/files/dilepubogajowigomakado.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/17216063496148f36a76a23.pdfIn PDF document text
    • http://portalpr-b2b.es/img/user//file/_0730826001631340745.pdfIn PDF document text
    • http://qazaqbanki.kz/data/content/files/fipazewo.pdfIn PDF document text
    • http://gojjang.com/uploads/files/55623524549.pdfIn PDF document text
    • http://www.louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/firipofi.pdfIn PDF document text
    • http://eco-building.cz/UserFiles/File/pezogaw.pdfIn PDF document text
    • http://2016.letnifestiwal.pl/ckfinder/userfiles/files/kupimopad.pdfIn PDF document text
    • http://philipwillettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/30673074160.pdfIn PDF document text
    • https://tpk-m.ru/files/file/fitivefepopu.pdfIn PDF document text
    • https://llibreriaha.com/img/events/file/fezovopofizog.pdfIn PDF document text
    • http://afro-safari.com/upload/files/rixopiporiso.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e4bceb0cee---1295051338.pdfIn PDF document text
    • https://barcelonacentromedico.es/files/galeria/files/birumofanojupop.pdfIn PDF document text
    • https://fobh.net/userfiles/files/nupasa.pdfIn PDF document text
    • http://debeight.net/UserFiles/File/57164825335.pdfIn PDF document text
    • http://www.dialog-seversk.ru/jsplugins/ckfinder/userfiles/files/37246326338.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=harry+potter+chamber+of+secrets+putlockersPDF 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_off0000bb3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB3E 19424 bytes
SHA-256: bbfb5d545e86284970529dafb23c18414d48fcf60b36bfe7751891bbecfa26c7
font_01_sfnt_off0000ed72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED72 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010589.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10589 10984 bytes
SHA-256: edd0d619353723d5fb62ed4bc7ba4b58e767d350add619245a23e5a9144ebfc2

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