Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8c04c91fdca4790…

MALICIOUS

PDF

72.2 KB Created: 2021-06-19 03:49:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 0d7c2c661f9183ebbd9ae677e27e223d SHA-1: ab0674bd12e93ac717ae4207673b073b064092f4 SHA-256: d8c04c91fdca4790dc936d65f7c2db17be6c88c46a7248f8e9e1ed94bdb37341
156 Risk Score

Malware Insights

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

The PDF file is identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It utilizes a link farm strategy, hosting malicious PDFs on compromised WordPress sites, to lure victims with a 'maths book pdf free download' lure. The presence of embedded URLs and the overall structure suggest an attempt to deliver a secondary malicious payload.

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://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609ee1a58a3e5---16359416155.pdf In PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1608261acd0bca---34334821410.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/a28e17658aa8da6e64b9b0c2f211cadd/64803425725.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/4bc133ef49cc9fce23764aa19886c7d9/gosapezeragijof.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/9700375468.pdfIn PDF document text
    • http://brandnewgoods.net/userfiles/file/gozomuposurubedenabufigif.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/jgoarhal5232efv4umnoe0jn7a/55765964227.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b850913a53a---87249546059.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160731485b7247---80651750724.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/90588029850.pdfIn PDF document text
    • http://novichiha.ru/pic/file/31893333217.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ab9fe648a12---83616797301.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/b9783cbf82f6bea49cd78d8895b1db0e/womigamorudufubanoraji.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095b0a0f0918---gufekonevew.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160984f6ed37de---3860624881.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/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=maths+book+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_off0000dacd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDACD 5428 bytes
SHA-256: 02c9d24be40cdcc309bb35c571eca7f5e846cdae1151125cd13063e4a98d2326
font_01_sfnt_off0000ed56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED56 10896 bytes
SHA-256: e9bc6abf6152899c41ae8abf75ec26c9ab79c38351acb39093751997f5b9edbf