Malicious PDF — malware analysis report

Static analysis result for SHA-256 25d6b2c703f4fccd…

MALICIOUS

PDF

93.0 KB Created: 2021-08-31 07:15:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 79e09ff3990808dc3ddc295629c2b24e SHA-1: 8a50cd367b5a2aab9381b0ea63d0de22103f8799 SHA-256: 25d6b2c703f4fccd72b6fb4fdc15bad57c2d37e483638b16b4d926a56716d341
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it functions as a link farm. The embedded URLs point to compromised WordPress installations and disposable hosting, suggesting an attempt to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking clear user-facing content but containing numerous links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 https://pixomot.ru/uplcv?utm_term=9+phylums+of+animal+kingdom
    • https://coopinproject.eu/ckfinder/userfiles/files/dixedusadazusubi.pdf
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16086c9b17f7a8---11036161186.pdf
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/2883a85a7e71e7bd1d1d2a1d5a87c7c0/34301107114.pdf
    • http://bogieclassof67.com/clients/71235/File/75635990682.pdf
    • http://manixcnc.com/ckupload/files/durumijosorovuvagaledag.pdf
    • https://baatco.com/ckfinder/userfiles/files/2506862915.pdf
    • https://masterjobintl.com/ckfinder/userfiles/files/losox.pdf
    • http://princeverma.in/uploads/files/vuwemanamadekegofogem.pdf
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160857415a890c---8006332817.pdf
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e7206d214f---22081469278.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160cd2c4709d2c---losejitamor.pdf
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160992638637d8---dovenurofesoxakusaroro.pdf
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a556cbad978---40121552516.pdf
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/4cshoq83p6jhj3kfb3e1vi8oin/zamonulojemagagamoruzu.pdf
    • http://aranysolyomfeszke.hu/editor_up/mowukuwuvawik.pdf
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b362d0d0af7---32432808811.pdf
    • http://silver1979.com/upload/file/24681287478.pdf
    • http://linpus.com/app/webroot/userfiles/files/biwusa.pdf
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b860784ca59---55651304758.pdf
    • http://sibleyestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/mugifupikegobavopi.pdf
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16104cc9202d2c---12886742732.pdf
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/d7a0b8a0f2e88c19983b848d3c28cf22/xewulokavijudarotoxa.pdf
    • http://aumnat2car.com/ckfinder/core/connector/php/upload/files/fudikelarawumeb.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_off00010646.bin
0919014a7b716367a7ba0e1930bfa536ba7f2b4f84dfa2f07c8602aa85e81de1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10646 10992 bytes
font_01_sfnt_off00011f63.bin
b171013205c0c87ae24475594857bd3cf6c57fe68cc9423bf38a0e3ec872084f
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F63 18204 bytes
font_02_sfnt_off00014e84.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14E84 16792 bytes