Malicious PDF — malware analysis report

Static analysis result for SHA-256 c83b8dee2aaf64b0…

MALICIOUS

PDF

85.3 KB Created: 2021-09-02 08:51:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: bb15b9a2b4dbe6dfce9959bbd87140ee SHA-1: 633da20bf7de6b5334f7070b84af6a9a36c10a60 SHA-256: c83b8dee2aaf64b038c03f9c5b79176bc31e39c51cea835fc3069641572c56d3
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains a link farm pointing to compromised WordPress upload directories, suggesting an attempt to host malicious files or redirect users. The presence of numerous unknown URLs further supports a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160804fe8a510f---pevowumara.pdf In PDF document text
    • https://numen-wow.com/userfiles/cloud//files/59577981297.pdfIn PDF document text
    • http://drivescuolaguida.it/userfiles/files/92942201059.pdfIn PDF document text
    • http://wrhs1967.org/clients/6/61/617565fc8afb9cc6d18abf932d248b7a/File/21501332844.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607875a7503b3---88363273364.pdfIn PDF document text
    • http://springhs1988.com/clients/a/a7/a70db2535ed58991dd9724faf9b165d0/File/37672497589.pdfIn PDF document text
    • http://instandee.com/Images_upload/files/50804947098.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1609641d7ec0a3---88829319398.pdfIn PDF document text
    • http://gursakaryahukuk.com/images/file/nigolipuditogolax.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/78d1b00c9f849dd53635075fb69d80df/burovumuzadoluz.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c370c51b493---98639133554.pdfIn PDF document text
    • http://ok-poland.com/userfiles/file/dejujoxovisevifejuxusu.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1610b237f58251---85455955560.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/ec606bcf207c6ae24d099d38fbb1cad6/bamomiguzabemediv.pdfIn PDF document text
    • http://www.clc-engineering.com/siteuploads/editorimg/file/gunixewujakuke.pdfIn PDF document text
    • https://indiantalentjunction.com/milan/media/11663285980.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161101757a5ca0---54757766585.pdfIn PDF document text
    • http://alfadent-volg.ru/images_uploads/files/72868430297.pdfIn PDF document text
    • https://rotherelectric.com/files/80689827151.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/06937a2906a9f09aea1594a2a3714c25/jewanovujo.pdfIn PDF document text
    • http://mulroyenvironmental.ie/userfiles/file/rukoxidikikupezuwi.pdfIn PDF document text
    • http://realfootball.gr/userfiles/file/fuluxako.pdfIn PDF document text
    • https://makeswebsites.com/clients/c/c8/c8c605999f3d8352d7bb792cf3fdb25b/File/savedelig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=write+the+beginning+sound+of+each+picturePDF 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_off0000e359.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE359 19488 bytes
SHA-256: 81dc2c84af980a88ae56230af5fb12e3e19e3e7dac3d2b8d213163c7f692214e
font_01_sfnt_off000115aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012dc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DC1 11084 bytes
SHA-256: f9517605441cc663c97fb94866e2f7c6d3c1cb7d903d5d5f5f4ff3831c35ef03