Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc16a51c2290e6aa…

MALICIOUS

PDF

69.9 KB Created: 2021-09-04 14:54:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 46c075c1b36507c59ac071206537ced6 SHA-1: c4258c97574a72fc71ec7043114e298fd94be951 SHA-256: dc16a51c2290e6aa23ea209c50c3e160dbcc89265f3ecd122d05a395f8459b82
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier. It contains multiple heuristics indicating it's a link farm hosted on compromised CMS uploads and disposable hosting. The PDF document itself appears to be malformed or obfuscated, with no readable document body content. The presence of numerous unknown URLs suggests a phishing or SEO manipulation attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/1dohkqv9395ah177e5npggckm3/sosipuwikuvesev.pdf
    • https://snqrsl.quebec/upload/editor/file/rulibasosog.pdf
    • https://dienmayminhchau.vn/uploads/news_file/53654931025.pdf
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160f84f5155d9e---konoga.pdf
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/dung933i005ijg9rej91rurkb2/mogozubuwibeber.pdf
    • http://jrpst.pl/userfiles/file/vewujova.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16118a3f6a63d5---texuvekaso.pdf
    • https://ka-base.no/images_content/file/37244086474.pdf
    • http://qunjl.com/userfiles/files/45261497423.pdf
    • http://anvlaw.com/userfiles/file/27774305841.pdf
    • https://bodwellassociates.com/wp-content/plugins/super-forms/uploads/php/files/e23fd88848bec57767dee7d3b384b000/89850743143.pdf
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/ca45lg3n7q064pot4g80d6h0lh/lajot.pdf
    • https://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/nl70m6avs9996thjlmr0bl4ha5/98617920911.pdf
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcc8b996343---42803344840.pdf
    • https://akproauto.net/nbloom/fckuploads/file/37428263226.pdf
    • http://paillasse.hu/userfiles/file/60148573275.pdf
    • https://celebicatering.com/upload/ckfinder/files/46435142317.pdf
    • http://apcmagon.com/userfiles/91987735664.pdf
    • https://travolution.travel/wp-content/plugins/super-forms/uploads/php/files/f09aea42199050f13f4f85dbacd8deab/nakugunosolovutakafo.pdf
    • https://www.alugutader.fr/ckfinder/userfiles/files/badisowaselisigigej.pdf
    • https://menu2uplus.com/images/file/ketesewutilezofunenoto.pdf
    • https://c-effeimmobiliare.it/file/51937124225.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=oracle+apps+scm+functional+interview+questions+and+answers+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_off0000b3d4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB3D4 16792 bytes
font_01_sfnt_off0000cbeb.bin
cc94efae5e2fe93bbcbf5e156d00322e6e8aa3f9dcbe49a29f960bb3596ea39f
pdf-font-stream PDF embedded font (sfnt) at offset 0xCBEB 11204 bytes
font_02_sfnt_off0000e5ff.bin
a13328623779d3a34712e97ecb36b26e2590e3a03a38df51789fee1241843f97
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5FF 14136 bytes