Malicious PDF — malware analysis report

Static analysis result for SHA-256 c72cb30f508ab1ef…

MALICIOUS

PDF

71.5 KB Created: 2021-06-24 22:03:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 5d28eb18ec4cffb8cf967b3708e7a5b4 SHA-1: b1e3d6a0842040de370a0292f54d74ee18197582 SHA-256: c72cb30f508ab1ef16d1d8d0d23f513f8dfcfa6c3ded02fa114d4e49f9e58aee
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous links to compromised WordPress sites, suggesting it's part of a link farm designed to host and distribute malicious content. The document body, though heavily obfuscated, appears to be a lure related to "cscs revision book pdf", aiming to trick users into clicking the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://catamma.ru/uplcv?utm_term=cscs+revision+book+pdf PDF link annotation
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/16231310133439.pdfIn PDF document text
    • https://evenimentecastel.ro/wp-content/plugins/super-forms/uploads/php/files/ir9gnfhev7vip2rl9i87ikge74/vutagerowupix.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1609381c723a12---75435227236.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/160833cfee8113---vemofividepe.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607fda05755f4---26079986342.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1609b9aec6e431---35715366805.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/f872f67334eb911bd7657e38b932e5a9/ravuk.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16082673ee2f29---mokebuworibozawerexeson.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed957f3102---liguso.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/d65291db955e6094ef6fe47c3b507f6a/97132908972.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/uvmlck10thmdpkqfnsvonv8ub3/48395479315.pdfIn PDF document text
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/657878bd6d5eb4f4e4fe1a2da9d6cd04/goxevajijivetajej.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/xobixigavu.pdfIn PDF document text
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/0m0t6rfdfqhncrn7umj125bnu0/budixoburazuzopig.pdfIn PDF document text
    • http://biomassasia.net/data_ed/userfiles/file/17213328026.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d8f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8F1 5076 bytes
SHA-256: f3e2467f8a75a7d41001c446151331d5a78548813f1e92dd667c26714a236dad
font_01_sfnt_off0000ea4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA4C 11628 bytes
SHA-256: 8354951572d05dcd0fc9ada4ec7473203e6b32cc1365c47342ebb657ff4d8108