Malicious PDF — malware analysis report

Static analysis result for SHA-256 a23b5f26fdf59f6e…

MALICIOUS

PDF

72.6 KB Created: 2021-06-05 18:59:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 465128e14cdcaeb91215af7896476972 SHA-1: 1f15425f6ea2c2e70bbaefcef1eb1056197d08ea SHA-256: a23b5f26fdf59f6e644a816f5ef6ae6fc5c495ef57c87cf203b23dfbb6f8e09a
156 Risk Score

Malware Insights

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

This PDF file is identified as malicious by ClamAV and an ML classifier, indicating a phishing or trojan threat. It contains numerous links, many pointing to compromised CMS upload directories, suggesting it's part of a link farm designed to distribute malware. The embedded URLs and the document's apparent purpose of mimicking search results for educational material point towards a phishing attack aiming to trick users into downloading malicious 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://oniceh.ru/uplcv?utm_term=6th+class+maths+problems+pdf PDF link annotation
    • http://bonfiremadigan.com/uploads/fckeditor/file/letapobibepugis.pdfIn PDF document text
    • http://schroniskoorzechowce.pl/ckfinder/userfiles/files/48498614203.pdfIn PDF document text
    • https://ukdirectremovals.com/wp-content/plugins/super-forms/uploads/php/files/68a5b7243569cc84406ee8818bc1d74e/zanividem.pdfIn PDF document text
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a0bd89e57a9---gisok.pdfIn PDF document text
    • https://dmvassociates.com/wp-content/plugins/super-forms/uploads/php/files/8f2ab99e814befce32a4833e58f1c64b/12278714598.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d65d3360c0---67930097504.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/ku3unc4potnlq384c3n4iqnkn8/60182156670.pdfIn PDF document text
    • http://vasvaripalmuzeum.hu/upload/file/33041978034.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609ec47415068---79794841153.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/5cb3aed6674d24d4d27773b0ca037eeb/pujemumerumo.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/942f447bc23b69af3ff462a5c8c97b7e/widudovizoxezekedepinir.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606da0f7247b7---xoparefadikusaz.pdfIn PDF document text
    • https://cedarcreeksauce.com/wp-content/plugins/super-forms/uploads/php/files/7f28c2dfd37c6a7b6ad44160778ad9da/55193997744.pdfIn PDF document text
    • http://adria-ex.com/images/blog//file/wosuzawifozuna.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b94f3a17f51---48234091016.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_off0000d150.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD150 5228 bytes
SHA-256: d7e139b5c329955bc07051406f23cd19a2d0e42134e6b7d99bc56e489a256856
font_01_sfnt_off0000e302.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE302 10712 bytes
SHA-256: c283732bb75c0f5744a2bc29eca1191fd896154fbb71a9a74792be01342b6745
font_02_sfnt_off00010780.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10780 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378