Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb8cf9fa5079f75d…

MALICIOUS

PDF

93.7 KB Created: 2021-09-09 08:01:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: c147f91ccd3fa4c7ceee5b8f2fb7265b SHA-1: 2fb5db0613a206991e7bfe96df26d06dba494e75 SHA-256: fb8cf9fa5079f75d7eca29306a21e050ec35884f67a841a8ed2304992b79904d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm used for phishing or malware distribution. The presence of embedded URLs and the nature of the heuristics strongly suggest this document is part of a phishing campaign, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://infrive.ru/uplcv?utm_term=codex+adepta+sororitas+pdf PDF link annotation
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/l7j3i6m1c0ing992aua5g5eek0/47568350761.pdfIn PDF document text
    • https://umiyawoodworks.com/fckdb/userfiles/file/duguvezafipipazuwiregajep.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/vq4udu40evs5th8efc31dfakpq/50436221400.pdfIn PDF document text
    • http://hycxchina.com/filespath/files/20210907234309.pdfIn PDF document text
    • http://birdwatching.sk/media/file/11819420111.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/16139306976aa6---binosofe.pdfIn PDF document text
    • http://djapm.com/userfiles/file/3002479571.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/u6jn2oo96udbglep5mivvvgjs5/tavezum.pdfIn PDF document text
    • https://gulfb2b.com/userfiles/file/89652078815.pdfIn PDF document text
    • http://otczenacts.com/media/files/19027576675.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/0e9d88824a272ffe1b9653b61342b7e3/dazosa.pdfIn PDF document text
    • http://evaemlak.com/userfiles/file///38474798202.pdfIn PDF document text
    • http://arsvet.ru/img/upload/vupebise.pdfIn PDF document text
    • http://cdio.vn/uploads/userfiles/file/telunarominogudej.pdfIn PDF document text
    • http://hcm-invoice.vn/hinhanh_fckeditor/file/jipumevokuxugapavobonabi.pdfIn PDF document text
    • http://yonseri.org/userfiles/files/sufuxepuko.pdfIn PDF document text
    • http://wedding-box100.com/uploads/files/202109050701092668.pdfIn PDF document text
    • http://exim5.hu/_user/file/divisa.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/kfeqcoi0omjan7c4cfsi2s5sgq/waboli.pdfIn PDF document text
    • http://na-bytecek.cz/UserFiles/File/25145209412.pdfIn PDF document text
    • http://louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/lamejupukenafep.pdfIn PDF document text
    • http://zubrcup.by/files/files/28645072869.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_off000104a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011cbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CBD 10476 bytes
SHA-256: 095841c7098e54f6de734d153d4dc7421463bf4311cb434222bb6a9226beceb0
font_02_sfnt_off000134b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134B0 19880 bytes
SHA-256: 669ef1fbaa6e68b37a352cab34ade2c95c0d203b5a34d3ed27e870cd5a93e022