Malicious PDF — malware analysis report

Static analysis result for SHA-256 c334538cd984b899…

MALICIOUS

PDF

67.4 KB Created: 2021-05-05 06:25:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: b6e89bd5a31650e36d85cac3354f292a SHA-1: 91766d15e441b0333f386a154020e38d0df277c0 SHA-256: c334538cd984b899a0cc795eca7775f73e6808756dcfce85f0606f4c73e0bf0d
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. It contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting it functions as a link farm to distribute malicious content or conduct phishing. The document body is heavily obfuscated and does not provide clear instructions, but the heuristic firings strongly indicate a malicious intent to redirect users to external, potentially harmful, URLs.

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://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/5c080a03b0453b88862b136fad43e958/koxuwumipasor.pdf
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/96dc41c035ff03d77703310b64b1ff3d/84233345090.pdf
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607855bcd93e4---5575922911.pdf
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079329c0186c---lobebi.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a95ca444c3---wujubukowobivaje.pdf
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073bd7397738---44972527978.pdf
    • https://alexandrapanayotou.com/web/images/static/file/fofos.pdf
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/eq9df1s9u4oeur2fgpqqo6rfnt/zuvibijamebejujidevusexa.pdf
    • https://accuratesearch.com/userfiles/file/42996159571.pdf
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/9a1891e853d50ddf34c104b9256f736d/zudarogiz.pdf
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/81e0b41a887e34a8034a71b1848540a2/16983085987.pdf
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607af8e87c8ee---80554222209.pdf
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/20baae83bf8881bb06b15520cabd7f0f/27641429714.pdf
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/d56fc5fc6d54cee827958c1cec3a19fa/jovakarepegorugas.pdf
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bb6c3aeedb---bepini.pdf
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/7m7kusbqs9kncklodpli4klb83/15824424358.pdf
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f0935ddfcf---96913123386.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=hd+audio+songs+tamil+free
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c7c3.bin
331620f6cf33725ce28b9f0279111b8149a95e9d760a16ead2f555ba1d7f306c
pdf-font-stream PDF embedded font (sfnt) at offset 0xC7C3 5188 bytes
font_01_sfnt_off0000d952.bin
4582f3be40d838f1a08151f612c9d761375f7d55a08a2e273445bd4404c9b202
pdf-font-stream PDF embedded font (sfnt) at offset 0xD952 12132 bytes