Malicious PDF — malware analysis report

Static analysis result for SHA-256 43c0c8ace8bc0d6d…

MALICIOUS

PDF

77.0 KB Created: 2021-06-13 10:36:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 2589bf59cafb795b152604bd8719c27e SHA-1: aa228c47399f54d73b98a6e823f2f0b98c87cd57 SHA-256: 43c0c8ace8bc0d6d6d33a85dd5248299e160325b19551bf2fb86e2e173f2586b
156 Risk Score

Malware Insights

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

This PDF document is classified as malicious by ML models and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, embedding numerous URLs that point to compromised CMS uploads or disposable hosting, likely to redirect users to malicious sites. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of multiple external URI heuristics reinforces the attack pattern of directing users to external, potentially harmful, content.

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://smidgel.ru/uplcv?utm_term=break+even+analysis+case+study+pdf PDF link annotation
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/bipudeki.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608c7299bf167---zagarolidurugava.pdfIn PDF document text
    • https://anmimar.com/royal/userfiles/file/31327551291.pdfIn PDF document text
    • https://deedpoll.sg/wp-content/plugins/super-forms/uploads/php/files/814a7518342611c90db9bf1be607e12f/4077777805.pdfIn PDF document text
    • https://lightspec.com/wp-content/plugins/super-forms/uploads/php/files/6e988d0f781d630e48e32d120f8d3548/tigezufakodasilirunekuza.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160b249445baa9---pelafarilaw.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607f09f3e898d---2690100003.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607a579dd5601---tibubobojex.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/67cd4276d8b3d9d6b0ab272df1e8437e/texovojilugabuteju.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/7c57e8c7330fbefcf5352f5f8bcb5e58/zowikoxasesiromijaxoke.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/f83b8ce9c7024b756d0aa38e1182a3a0/63365282360.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/7mriuod69k2t97af7t9ui4s5h4/zajiluduretid.pdfIn PDF document text
    • http://amadpich.com/userfiles/file/kaluvivagevesavafotituw.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e3b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3B9 5196 bytes
SHA-256: a424fb24ff61ce8ea8bd7ff0ca4d8a55cc6fc50219d3996fb74d517588c6962a
font_01_sfnt_off0000f57c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF57C 10420 bytes
SHA-256: d9829d2cd30a99ed15746c14ebfe60bc89a82bc7e0d6a5c84e4bd04c534cd2a5
font_02_sfnt_off00011929.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11929 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3