Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8431ab957f268d6…

MALICIOUS

PDF

76.6 KB Created: 2021-06-12 17:47:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: f203604dbd653d91b23830dcb1c7fd6e SHA-1: 876af823db92a4f6cc7cebb4949245294b9650c2 SHA-256: c8431ab957f268d664cd7d3b41c7c7d1cdcbe1b2c2e273c6028753bf9d96759a
156 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

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://ketchas.ru/uplcv?utm_term=energy+transfer+in+living+organisms PDF link annotation
    • http://novichiha.ru/pic/file/65019023537.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/2503c6f0d50b704a635e11f165417785/56624425397.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/5c4331159eb3817218ab878f36a9f392/75488871223.pdfIn PDF document text
    • http://gd-weimi.com/upfolder/e/files/20210529131427.pdfIn PDF document text
    • https://bayardplaza.co.uk/wp-content/plugins/super-forms/uploads/php/files/2dh0v86vsrn3nht2333ase4v1s/mitozawetifupigalugu.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/gijuzinutij.pdfIn PDF document text
    • https://caribemed.com/userfiles/file/pirogivopamufamuj.pdfIn PDF document text
    • http://auapp.ch/userfiles/files/90425500513.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608af18a08d9b---26092988513.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/cdcf424b4209c9b4b49ecc6ef4c97a4b/95445078644.pdfIn PDF document text
    • http://alexanderjamesbackcatalogue.com/userfiles/file/fujuronuwedipaguvomog.pdfIn PDF document text
    • http://edgecs.net/documents/taxibenira.pdfIn PDF document text
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160844bacbc4fd---pulegodifodebomigukit.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae5e9595ef2---mabiv.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000edcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDCC 5204 bytes
SHA-256: 3e871048ddc4ca4f1fac0ce415bb29c444970c810ca2a3a9f4f3136232d8006a
font_01_sfnt_off0000ff83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF83 11172 bytes
SHA-256: 6c6a9261ed6dd035334707535ccfff26afd2668efdefc5194746a4a1ee57e38d

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