Malicious PDF — malware analysis report

Static analysis result for SHA-256 c923da3bce7c7506…

MALICIOUS

PDF

81.1 KB Created: 2021-08-05 15:01:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 773e04618dd3efb16365479367058e7e SHA-1: 4a6897fa5d16d08f6ef3be138adb2b92069425e9 SHA-256: c923da3bce7c75063c7a14ce40ef37177c26c0a0e78c9ec0bda12f550ebb80b9
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to lead users to malicious content. The ML classifier and ClamAV detection strongly suggest a phishing or malware distribution intent. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://cructi.ru/uplcv?utm_term=vertige+de+l%27amour+chords PDF link annotation
    • http://xingyeknitting.com/userfiles/files/6651423055.pdfIn PDF document text
    • https://markmont.eu/editor_uploads/system/files/28671918731.pdfIn PDF document text
    • http://synthecinter.com/userfiles/files/94184871060.pdfIn PDF document text
    • http://predit.ru/admin/ckfinder/userfiles/files/joligobogifenigewabinu.pdfIn PDF document text
    • http://wohntraumgmbh.at/rimenipi.pdfIn PDF document text
    • http://www.doctor-carpet.com/wp-content/plugins/super-forms/uploads/php/files/favv0mgogloei9hgoeth8m86b3/tokokuninisivodezodo.pdfIn PDF document text
    • http://kinel-hunter.ru/upfiles/file/40959024565.pdfIn PDF document text
    • http://gumberryoleschool.com/clients/33891/File/21808050161.pdfIn PDF document text
    • https://bartonsteel.com/tony/barton/ckfinder/userfiles/files/gubuf.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/fbc3eb7e81rr2v8fujjt76gj48/xifasoped.pdfIn PDF document text
    • http://tiramisu-o.com/yamituki-n/uploads/files/94297273818.pdfIn PDF document text
    • http://serdceprirody.ru/userfiles/file/kixaponu.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a51669f28af---dilajumenolavavab.pdfIn PDF document text
    • http://mexxeopaint.com/upload/files/72525792147.pdfIn PDF document text
    • https://arichaindia.com/userfiles/file/15387532481.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098443fe6b0e---mejemulozedunixos.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a732005b9ad---42233008998.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/078c7736c9ffcfe43631436ca65808b9/fufimivorimetegobudidexuv.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160862abd195df---91898833833.pdfIn PDF document text
    • 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_off0000d3d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3D1 10816 bytes
SHA-256: cfce2ad800ab9b3426e20055424491f9c5f2533bec57e518668196661989fabc
font_01_sfnt_off0000eca7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECA7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000104b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104B9 19028 bytes
SHA-256: f54daf8f70d989e71c78243273889ad9e21d0704db20168a344f45b8ce21b1c6