Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c20bc82876b4384…

MALICIOUS

PDF

98.2 KB Created: 2021-06-29 23:45:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 28b83135d8798551ad39b1007714a69b SHA-1: f6ee348e82337a119ea14b6d93981aa9a6594c9d SHA-256: 4c20bc82876b438472a61b8c4818917877989c532d5f058a7831df9327808ff1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of links, many pointing to compromised WordPress sites, which in turn host other PDFs. This structure suggests a link farm designed to distribute malicious content or lead users to phishing sites. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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 http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/16094bccc29f36---77369294944.pdf In PDF document text
    • https://www.wflorlando.com/wp-content/plugins/super-forms/uploads/php/files/4d5060170c475acac0508b187ce6c94f/xomuxotu.pdfIn PDF document text
    • https://planet-for-events.de/userfiles/file/51120913944.pdfIn PDF document text
    • http://xaydungphongphu.com/uploads/files/laxax.pdfIn PDF document text
    • http://kojeneckezbozi.eu/userfiles/file/pixowejilodopilazik.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160723c11c6634---46458986950.pdfIn PDF document text
    • http://otelm4b.ru/admin/ckfinder/userfiles/files/5597948465.pdfIn PDF document text
    • https://asiaviews.org/wp-content/plugins/super-forms/uploads/php/files/ml9epjvf9o6f5sj53qcnnutfu5/18121322813.pdfIn PDF document text
    • https://www.propertyfilevault.com/wp-content/plugins/super-forms/uploads/php/files/43133bec1afbccaeec6f0831bd5b5777/7880640094.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608165690a5b9---39159701314.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/98804257601.pdfIn PDF document text
    • http://k-yoga.org/file_upload/spaw_upload/file/20210519100934.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160ac7e9c26a46---13057782250.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160b1087a9097c---dopovobusijadefemevagezok.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/16086df6cb9945---88439025720.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/fa2355764d19b7c33da96314bb611ffb/24516847829.pdfIn PDF document text
    • http://bonfiremadigan.com/uploads/fckeditor/file/76415077296.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8bc637ed9---39355897864.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/773dd95e72a8f9f8d633762b96f98880/70927825770.pdfIn PDF document text
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/u9oasbfvo6ttfeurcqll3nmot6/ruravegajor.pdfIn PDF document text
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/e5207a268bd801296aa483b346058e44/46473374434.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/fuzesuvetiwatarafewuviv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=dr+khader+books+in+kannada+pdf+free+downloadPDF 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_off000115fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115FC 20152 bytes
SHA-256: 4316265451226a1c34dc65cb99a3d7cb92f38e205c65d6869ae86dc30d460561
font_01_sfnt_off00014adf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14ADF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000162f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x162F6 10816 bytes
SHA-256: 7763184332ce5945b31dd336c7dc0b7f769744ab32d5b3895364e2e315eec18a