Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbef1ad388a4f0c0…

MALICIOUS

PDF

74.4 KB Created: 2021-09-17 20:05:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 56ea34efd725c5255bb999ad8209703e SHA-1: 3e376e923039ae933b60c9aaf1e7782e18b9f275 SHA-256: cbef1ad388a4f0c02627d30a7160726d93d57a1f04b2bfbf89627f551692fb88
156 Risk Score

Malware Insights

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

The file is a PDF containing numerous embedded URLs, many of which point to external files. Heuristics indicate a 'link farm' pattern, with several URLs hosted on potentially compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://kcntanduc.vn/img_duhoc/files/93800114896.pdf
    • http://nm-union.ru/ckfinder/userfiles/files/patudikokefipowerel.pdf
    • https://haciendaloscipreses.cl/upload/file/pifeg.pdf
    • https://ingatlansos.hu/images/userfiles/file/95568012821.pdf
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/s7kgdkr99so67n24a8rdtn3fvv/96974448555.pdf
    • https://kaimano.it/file/66999402267.pdf
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/qkgbcpusrijbjhmfho32o2v8h6/97690448844.pdf
    • http://dolphinkorea.com/files/files/sogesafot.pdf
    • http://archiprojektai.lt/app/webroot/uploads/userfiles/files/jimew.pdf
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/16143dc04e1f3d---sikaxogiwoxos.pdf
    • http://dreesmann-foto.de/userfiles/file/kepipepelekoxagobipirota.pdf
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138a57a56f1e---48687140317.pdf
    • http://thestarbusan.com/FileData/ckfinder/files/20210903_80C12132A3E60750.pdf
    • http://sartor.ru/upload/files/lozogolafitokusi.pdf
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f9b2828cd9---mozig.pdf
    • https://ahirealty.in/admin/userfiles/files/daneserumefalabapevanatov.pdf
    • http://dungcumaymoc.com/Images_upload/files/forodafonafuxexos.pdf
    • http://xn--nellieskche-0hb.de/userfiles/file/77160497370.pdf
    • https://dobski.pl/userfiles/file/jesoge.pdf
    • https://papersacksfactory.ae/images/bulk_images/files/5628854286.pdf
    • https://oolong-dining-co.com/webroot/editor-uploads/files/62918548397.pdf
    • http://dh-life.com/ckfinder/userfiles/files/75649216818.pdf
    • https://hefcom-hydraulics.com/ckfinder/userfiles/files/lolenegowigivufiwobiza.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=rally+fury+extreme+racing+download
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b8f9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB8F9 16792 bytes
font_01_sfnt_off0000d110.bin
e67ad331778b685e7f9db10e7e4862f895453f55f488f9f675ede64d2ed81687
pdf-font-stream PDF embedded font (sfnt) at offset 0xD110 11100 bytes
font_02_sfnt_off0000ead0.bin
3e16d12fc9df776b02d5246a4f6d1ce31ee46ba840e61c2692e2ba7877703185
pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD0 18872 bytes