Malicious PDF — malware analysis report

Static analysis result for SHA-256 528da97d99ca7c20…

MALICIOUS

PDF

142.9 KB Created: 2021-06-14 02:15:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 3b3f095b7226c81643b92b9fc7e7d96c SHA-1: 731ded681de845805ae9be75c71087eb498f7fc9 SHA-256: 528da97d99ca7c20660236cd215fdad2918800cc4e7985a4ad7643130a4af884
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, but the extensive use of external links is a primary indicator of the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://drafthe.ru/uplcv?utm_term=kanji+and+hiragana+chart PDF link annotation
    • https://refour.dk/wp-content/plugins/super-forms/uploads/php/files/43d6a614973b438bf11acecb836fed54/34806358959.pdfIn PDF document text
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160a0456302c58---buzoputuvuf.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16082322e4ca6a---69438526489.pdfIn PDF document text
    • http://davidhammerstein.org/userfiles/file/jagol.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084646dce167---28583947068.pdfIn PDF document text
    • http://fluitec.fr/ressource/site-image/files/95843033353.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/43bce82cb490d77cd83c78df0fdaca46/42691982821.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609847ec785ab---lujasowamujumagajiz.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609833f88d081---53033782983.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/16078313b9e553---82885581250.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3f9fe85426---napegusirakejoserezip.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b0789773519---14971178781.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ac50ee9bfc0---85068168980.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/6795b5735ed6bcbc3f64f4245a215a2b/zevavawuxax.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/db483462745b46e83d5712be6d8ba1e2/99532102860.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/4392ff1c4e0c29f78df1492757f1d873/guxupulubixotudumi.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001457b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1457B 49856 bytes
SHA-256: 37bfe061db9e741f53d04a2ddb318ae56c897ba811d36da9e84d6cd7bf95807f
font_01_sfnt_off0001d837.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D837 5036 bytes
SHA-256: ca5710d55f8ac898c6bc1d2185b8b9468b3536920684bfdc931fcac0f46a039b
font_02_sfnt_off0001e95d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1E95D 14968 bytes
SHA-256: c67246eb4cbf16e18f980de048d14e6bdda9eeb492c6b8da643cedbaafcc5b58
font_03_sfnt_off00021812.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x21812 16332 bytes
SHA-256: 469db9f955e15fa9795508df556129481e926c2a93d534bce5646bdbca8ade14

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