Malicious PDF — malware analysis report

Static analysis result for SHA-256 c51760508033f752…

MALICIOUS

PDF

89.4 KB Created: 2021-08-05 10:05:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6cb83b465253bd9117f0bba3db5e50a5 SHA-1: c56d32887a84a7cd19de52df1adaa90ac49dab3d SHA-256: c51760508033f75267f04c3049d24e93e89b1eb324f4d7ca7ac7c617d285eb3f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is a PDF identified by ClamAV as a phishing trojan. It contains numerous links, many pointing to compromised websites or disposable hosting, suggesting it's designed to lure users to malicious sites. The ML classifier also strongly indicated maliciousness, supporting the phishing and potential malware distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://bclgrouptt.com/userfiles/file/17800300814.pdf
    • https://mobistore.co.nz/wp-content/plugins/super-forms/uploads/php/files/32746cb3f25b2fc005e625b0cc0a9153/katuramapapi.pdf
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160ee298c7f518---40208438336.pdf
    • http://7seapharmtech.com/Uploadfiles/files/gulos.pdf
    • http://healhumanity.foundation/userfiles/file/jimuwenolezaguxazogexipo.pdf
    • http://orem.mn/uploads/files/27813467745.pdf
    • https://pfhotel.gr/ckfinder/userfiles/files/512610426.pdf
    • http://ifa-astrologie.de/userfiles/file/87076689735.pdf
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc42730ae58---19060401798.pdf
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/qjnfn0dmgkfun99jqbd7rcksa1/80220205179.pdf
    • http://aow.infogestnet.it/ckfinder/userfiles/files/wedoxofudusevolonur.pdf
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160df92750c063---15328132598.pdf
    • https://www.couleurs-et-jardin.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608299676a89e---bedipewi.pdf
    • http://avstralianature.ru/ckfinder/userfiles/files/bumugivuf.pdf
    • https://textosolutionslinguistiques.ca/upload/editor/file/berule.pdf
    • http://billedbutikken.dk/articlefiles/file/93959216646.pdf
    • https://doctornhospital.com/banglanews24/editorsfiles/files/37695857937.pdf
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ae3a732b344---zesaz.pdf
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/5f7118deb77bf479ead730b1c9521982/58195956660.pdf
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160964a64763f1---defevanerupeduxaniwurifu.pdf
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a773af7bc15---78206113230.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=social+anxiety+disorder+questionnaire+pdf
    • 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_off0000f9c1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9C1 16792 bytes
font_01_sfnt_off000111d8.bin
cac37bb254b8b578b6b6011bbc39fd4a99be69d3396ad7c8e6408d181dd0e389
pdf-font-stream PDF embedded font (sfnt) at offset 0x111D8 11152 bytes
font_02_sfnt_off00012bcc.bin
ab76df46634a6d8ed8d107e4e0558bf35133eb62d9cfb1dce544efd70a43b022
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BCC 16896 bytes