Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e01f09a5061569d…

MALICIOUS

PDF

81.0 KB Created: 2021-06-22 17:46:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: b4065b6226c22450dc31afc4632d4b36 SHA-1: dd5739b356ca89c7837745b55c7768ba6b630b1b SHA-256: 8e01f09a5061569d84d104aab0efcc8f603d6b77528b45c919667ce6e4fc3cdd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The 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 hosted on compromised CMS uploads, suggesting a phishing or SEO poisoning campaign. The document body, though heavily obfuscated, contains text related to 'Entrance exam questions and answers', likely a lure to encourage clicks on the embedded malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nomylo.ru/uplcv?utm_term=entrance+exam+questions+and+answers PDF link annotation
    • http://monkey-do.net/userfiles/file/63094772603.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/1757d190c71fd4b04894ca09be8cc3f2/zoxutiwoxexifuvu.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b22e7d3985d---juribomomawaririlemu.pdfIn PDF document text
    • http://dzbnf.com/upload/file/%5C/78054913160.pdfIn PDF document text
    • http://bakoca.hu/files/file/vovumudewatikepegam.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607041e5e8d8e---92698510396.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/160abf60a2f7dc---jevaxagifus.pdfIn PDF document text
    • http://adams-gold.ru/archive/image/file/narizulibofeboserakebe.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074cfcdd16df---32121129664.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/c1bfa1c0c9663baa18c93f50a50c716a/robariponiwarudotevofeza.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093bfeda8171---82203195731.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a6afc51a934---65354469673.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/79o8s4g1jdifsmhm8b17ka6epp/37957293680.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/n5rtpagbfllsv4jhp75lg08jq1/40564165076.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000f3e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3E9 5296 bytes
SHA-256: da473db80a9d2c1c45ead0513f89e49d6949d5bc95e64ad39b095fd4b46f9da2
font_01_sfnt_off000105de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105DE 1940 bytes
SHA-256: 9717c572b491d895217c4e958acc8dae43b5536372e998b1a3c12f26fa080abe
font_02_sfnt_off00010f18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F18 11836 bytes
SHA-256: 75db30e157df0661a80c22240bc6b4b644b052823316165c736e6ce89d99e41b