Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7920edd6bdf4068…

MALICIOUS

PDF

74.9 KB Created: 2021-06-21 10:14:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 6db9be285f5ce6960c387f97fe85d98a SHA-1: 60decf494237fa6cc65a6be7e20edfaf8251756d SHA-256: a7920edd6bdf406815d61fb89acd0a5facf4c7d023323e0c215c85262978b399
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload sites and other disposable domains. The document body, though heavily obfuscated, contains references to 'Gta online shitzu hakuchou' and 'wkhtmltopdf', suggesting a potential lure or disguise for the malicious links.

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://tskrea.com/userfiles/file/kaxobujokined.pdf In PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160c30fa169f71---zakoxewa.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/83582276175.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/d4ecda9485b9ab789522153e34e87b8f/kafixenuxokul.pdfIn PDF document text
    • https://signika.pl/Upload/file/62795528714.pdfIn PDF document text
    • http://www.greenbriarpropmgmt.com/wp-content/plugins/super-forms/uploads/php/files/af6543430becd2dc7c119928dab0eb8b/90422601585.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/eh80iqnp07sn29ftir150ufl4h/35837545615.pdfIn PDF document text
    • https://agrachoff.ru/wp-content/plugins/super-forms/uploads/php/files/356d60677678484c6d570b1c1906e164/fukadetadisexojezof.pdfIn PDF document text
    • http://agnieszkapawlik.com/userfiles/file/ronofudobujabipor.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/repajoxakar.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/e9bd27ea990a5c75bfc8f56b45371c0a/95664480718.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607911c9185db---jivokubotiko.pdfIn PDF document text
    • http://clubselectionvoyages.com/images/file/fewuti.pdfIn PDF document text
    • https://jnfarley.com/wp-content/plugins/super-forms/uploads/php/files/59knfd7b3npo1mun0129qr4t56/89667145573.pdfIn PDF document text
    • https://daleplumbinginc.com/wp-content/plugins/super-forms/uploads/php/files/7e8feb4288877dd367eaa71a357ae88b/34179373747.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=gta+online+shitzu+hakuchouPDF link annotation
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d7a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7A1 3680 bytes
SHA-256: c24bb6d74c43adac0f8214d6bd573a5201552c98ca71b272eb29176e387d30bb
font_01_sfnt_off0000e4b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4B7 4936 bytes
SHA-256: b22c7fbd20642955284d89f0d2b8c14e51f94de5afe97d5c66ff5cacd553de61
font_02_sfnt_off0000f588.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF588 11940 bytes
SHA-256: a334744cd2ee07f215690793eda4a86959c507e4ae401b166a3b9976216fa899