Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec86e7b46570e1a7…

MALICIOUS

PDF

71.1 KB Created: 2021-05-10 08:36:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: d3eacc990036186da12204fa6400864f SHA-1: ee46ae8a6210bf27e6b0a83db800a6adc652c111 SHA-256: ec86e7b46570e1a7efe0d936210df55b6f921f56d400b6c17cf033284a283a37
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to various compromised WordPress sites hosting PDF files, likely as part of a phishing or malware distribution scheme. The embedded URLs and the PDF's structure suggest an attempt to exploit users seeking free mobile games.

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://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608aee33e14cb---gafusawonadamexedisesusi.pdf In PDF document text
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078861030405---76381940865.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077cce9d5455---65828022254.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607545d04c647---2896562863.pdfIn PDF document text
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/4c09011bd314611a4e243ab0d05c6a14/bawulajawepegur.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160706ce68cf07---792280662.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/rgsocfh8o6vol3hdr7srhh10t1/33777691042.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2b152e89e---94696790997.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/vl2i18jrhhrdffobc89e0vtrs5/sojagupepuvawid.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/irvlsrkrc8a8bsvi2tbd3imt70/17328201068.pdfIn PDF document text
    • https://medprobr.com.br/wp-content/plugins/super-forms/uploads/php/files/9767128add8d9def9031a218ad00c622/tilebejinijidivasa.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160894664b06e6---92982608321.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160759387961cf---kitulanuxob.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/a4pp8rguamoe78r7v3ctd9mm85/18486848068.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608608c3b65f1---92624547090.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/Om9ozkHLxGw/uplcv?utm_term=car+game++free+for+mobile+apkPDF 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_off0000dbcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBCD 5152 bytes
SHA-256: efd2492cb7229be7b948f552c0b79f83439c6b138b3c8736daf514b59e454ff6
font_01_sfnt_off0000ed44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED44 10108 bytes
SHA-256: f30941ac2f5a751f773e9f70f06520c82f3166b62a5d3dccf5b7647a168f7ceb