Malicious PDF — malware analysis report

Static analysis result for SHA-256 a87fec84556ceffe…

MALICIOUS

PDF

76.1 KB Created: 2021-09-26 10:51:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c4bb825f374f7211619651baa42739af SHA-1: 8cfbe7ad2dcac4cc874a95228606aa0abf91e48b SHA-256: a87fec84556ceffe2152bca9b6f779c8585508c9adb879c4bbf580cdcbabae62
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected by ClamAV as a phishing trojan and flagged by an ML classifier. It contains numerous links pointing to compromised CMS upload directories and disposable hosting, suggesting a link farm designed to redirect users. The primary attack pattern involves exploiting the PDF format to host these malicious links, likely leading to further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://pianotuningdarwin.com/userfiles/files/fasenupomijuw.pdf In PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614398b44ddae---pojelo.pdfIn PDF document text
    • http://imhkayseri.com/resimler/files/wonaxusepibulake.pdfIn PDF document text
    • http://rana-international.com/userfiles/files/kozixizaxifapo.pdfIn PDF document text
    • http://playeasypiano.com/resources/fck_images/jajijugutujopesujoz.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c08065059f---11287792046.pdfIn PDF document text
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/fd5613b7014e795b4b906b324104fca3/11924670183.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/161497b5b73bab---rasazetujidal.pdfIn PDF document text
    • https://bhsbeacon.com/FCKeditor/file/82808210804.pdfIn PDF document text
    • https://banerjeetourspecial.in/ckfinder/userfiles/files/bubebijig.pdfIn PDF document text
    • http://flairpens.ru/uploads/file/36618707095.pdfIn PDF document text
    • https://bnbtravels.com/ckfinder/userfiles/files/25208748000.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613caa17cc6a7---87758151375.pdfIn PDF document text
    • https://obermeyer-modemarkt.de/upload/file/bekoxabixab.pdfIn PDF document text
    • http://thedreams.cz/files/wukerilajufadaf.pdfIn PDF document text
    • http://www.louisianarebarcontractor.com/editorimg/file/2494102167.pdfIn PDF document text
    • http://aquaclub.hu/userfiles/file/96492027910.pdfIn PDF document text
    • https://ikuseikyokai.jp/ckmedia/files/80448741670.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140cf9987c82---bedixijavibawigopafuser.pdfIn PDF document text
    • http://onroerendgoedindex.nl/images/uploads/92113615418.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb3d2cb956---41361672441.pdfIn PDF document text
    • https://navoloki.mebel18.com/uploads/files/xanimeseninugef.pdfIn PDF document text
    • http://lsphc.com/userfiles/file///mufimofixozakikasisi.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16132447753129---vasivalalunenemizow.pdfIn PDF document text
    • http://www.tokyomagic.jp/images/library/File/viruvo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=blackmart+online+storePDF 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c2ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB06 10536 bytes
SHA-256: cde5992d7bcd098d758d9dc8f4ff745b8df9f7b0a5408133d9f57353d2a45374
font_02_sfnt_off0000f307.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF307 18736 bytes
SHA-256: f9b1d0c0c44e98f332b8eda4bcb19e3403489ab6aa17a2688beef17e00bd5acc