Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8a7b44b8f0ff59d…

MALICIOUS

PDF

84.6 KB Created: 2021-06-26 14:00:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9f58977c935bc91e7b77df5ef20deaf6 SHA-1: 583b23e3461f09b2aa7dc02dcfbabb9af8e905e0 SHA-256: b8a7b44b8f0ff59d9ad683bef682d30ee1b7cf9304f38b4dba971ecc040c3900
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The primary attack pattern involves luring users to these external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://inwebjor.ru/uplcv?utm_term=knee+tibia+fracture
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1fc9861d3---40218996619.pdf
    • https://www.cpro.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160781897b96c5---vosalijivorot.pdf
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/ac5894c022f5ec440b87a38a0f52edd0/tizukufebunigopinewaw.pdf
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/29345d9165ef2744f9d444e77a6039b6/bizowifez.pdf
    • https://www.freshstartdigitalmarketing.com/wp-content/plugins/super-forms/uploads/php/files/537e6a4223bfad894a986bcc965ac282/98329564455.pdf
    • https://bandotrading.com/uploads/file/44531946477.pdf
    • http://ahdongjiu.com/upload_fck/file/2021-4-29/20210429023309270118.pdf
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/16078962d4170a---6745709414.pdf
    • http://bjallstar.com/upload/file/14720273704.pdf
    • http://www.assignproject.com/wp-content/plugins/formcraft/file-upload/server/content/files/160876a0fbacdf---62938287189.pdf
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/0fad29ad0bf169860ba7d0283fdda264/bigunefo.pdf
    • http://www.deep2001.com/images/library/File/wopujilulata.pdf
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/e8fa2f3fdfe46a9b21e5d410f23857b5/fisajuwasokuduvo.pdf
    • https://hagepoorter.be/files/files/51442490498.pdf
    • https://spacio.hk/attachment/file/veguniferipiwoko.pdf
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1606ed247db790---60601118349.pdf
    • https://electrabicycles.pl/app/webroot/uploads/file/16216484114919.pdf
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/3f2b02952e615577a33c9cc1153efd51/pedoguredawejo.pdf
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074485d6a3cd---zipusuzamagudirevame.pdf
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b086f5dbddb---gizil.pdf
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af58e30d9f9---2930628158.pdf
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/decbff4fc5cd89e7cccc55e74f743839/kodakixerasumowo.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eca6.bin
08bfde7a2dd3399833f6624c9f97e9830e59d3e28e28ced8de07e323b2e5fd3e
pdf-font-stream PDF embedded font (sfnt) at offset 0xECA6 10224 bytes
font_01_sfnt_off000103be.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x103BE 16792 bytes
font_02_sfnt_off00011bd0.bin
8b059e89dce9f7fe06da5618e38d7d7b034b2fe054f6f4d627f336b290471389
pdf-font-stream PDF embedded font (sfnt) at offset 0x11BD0 16256 bytes