Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ac40d44cdbdb429…

MALICIOUS

PDF

109.2 KB Created: 2021-06-25 13:46:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 749111e36d5d7edda0cca7d2ba610df1 SHA-1: 2e0c1f67c4ad246a0eab107a5f1dc05fff094735 SHA-256: 6ac40d44cdbdb42939b7d4d143f4a6114c38e4a303e6c6078a9b2793bd67526f
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised WordPress sites hosting other PDF files. This behavior is indicative of a link farm designed to distribute malicious content or lead users to phishing pages. The ML classifier and ClamAV detection strongly support its malicious nature, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://oniceh.ru/uplcv?utm_term=shoes+upon+the+table+lyrics PDF link annotation
    • https://airflow-skateboards.com/userfiles/files/wubowulisoxefefutunowaru.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/m8hif66d017910m3ungo0dafhe/xefebuwogefa.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/0a7bb04df92ea4349d6e80b19c2366a5/nuvejopetuv.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/160a7b3e0bd03f---77580904013.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4ca43ba0f4---mubepomidakilesok.pdfIn PDF document text
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/jtngi7papqv99m3v1fmmmer8p9/67030243154.pdfIn PDF document text
    • http://apluskleaning.com/admin/images/file/72112787705.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/4926ab925003da34dd26956438e67733/lujadogipukexidekexovum.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3065fc388b---binugazoposo.pdfIn PDF document text
    • https://flyags.com/editorResources/file///nepemibebenozuba.pdfIn PDF document text
    • http://ledson.ru/upload_picture/towifigowudurudesifok.pdfIn PDF document text
    • http://nkcophs50threunion.com/clients/0/01/014062e559e26c1cf0711bcec4e573ae/File/80686809520.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4f4a98f5f0---13887494406.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/2r66smggd2nsd5oueabotb0eo7/78595077476.pdfIn 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://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_off00014b73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14B73 17012 bytes
SHA-256: b4b1325d9ef8c77ca4e752d5cb78381deec89004d0e675a5cd72f01dfea283b7
font_01_sfnt_off00017788.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17788 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00018f9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18F9F 10900 bytes
SHA-256: ea33b040bc5e86741cac822cdbec2e3d5aac1efb82a6c80c48ea76f8a8317145