Malicious PDF — malware analysis report

Static analysis result for SHA-256 28c2c1b248f4d262…

MALICIOUS

PDF

70.6 KB Created: 2021-06-19 01:24:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 79c4d321f39eb1ac0a0989f133abe2d5 SHA-1: 8718c510b1099f2816ca4a979900538138d84773 SHA-256: 28c2c1b248f4d262d02f159d294dd6f091e8124c23d11405ef3197e74ac169cf
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS upload directories and disposable hosting, suggesting a link farm used for SEO poisoning or distributing malicious content. The document body, though heavily obfuscated, contains metadata related to 'scrum mastery geoff watts pdf free download' and 'wkhtmltopdf', which may be used as a lure to disguise the malicious nature of the file. The presence of external URIs and compromised upload links points towards an attempt to redirect users to malicious sites or download further payloads.

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://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/rsshpsiqgecnokmu99anl5l4nd/71991452791.pdf In PDF document text
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/490e5c61505738e901156c365f78c602/24862775689.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608339b20125b---12119009276.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/77171700173.pdfIn PDF document text
    • https://equantumconsulting.com/files/files/96729145088.pdfIn PDF document text
    • http://www.herbertvanderbrugghen.nl/draft/zetijagivovipetosa.pdfIn PDF document text
    • https://jxloanchien.com/style/postimage/file/17683692789.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16079242296037---63533074056.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/6766471108dea8556064906eda73ee3a/88899597279.pdfIn PDF document text
    • https://erdemlerkoleji.com/resimler/files/57259596165.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/3dc750a7e210b14d99947e5f8cebfd1c/80394011368.pdfIn PDF document text
    • http://omni-links.com/images/blog//file/neben.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/tutijaf.pdfIn PDF document text
    • http://yamamatoen-wanwan.jp/ckfinder/userfiles/files/kezivebodawakug.pdfIn PDF document text
    • http://adria-ex.com/images/blog//file/fijuwexemeboxubotedatumu.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c9b06f46d9c---73267149337.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/Om9ozkHLxGw/uplcv?utm_term=scrum+mastery+geoff+watts+pdf+free+downloadPDF 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d1ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1EA 5772 bytes
SHA-256: 79699baec9e4c7745632202f8ed57528d32384c00debd8552749ffd5fb406335
font_01_sfnt_off0000e595.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE595 11888 bytes
SHA-256: 9d38315b2bb624bee932df08532889a7d60f403b5ac1ed8c490108573c04fdbe