Malicious PDF — malware analysis report

Static analysis result for SHA-256 760cea7ca0906cb1…

MALICIOUS

PDF

91.1 KB Created: 2021-08-23 12:18:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 2df4a9ff6d7069b280fd57bbbfd692c4 SHA-1: 913994832a1a50782b0e91543a16f240984ccfaf SHA-256: 760cea7ca0906cb17ffcbb54504391dbcb96bfae38524968728075130f8c1431
96 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to WordPress sites that appear to be hosting PDF files, suggesting a link farm for SEO manipulation or to distribute further malicious content. The ML classifier strongly flagged this PDF as malicious, and several heuristics indicate it is part of a link farm hosted on potentially compromised infrastructure. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 5

  • 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://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/gjla57fkaui79oib8t4ucg23vn/32756124928.pdf In PDF document text
    • http://ferramentabelleggia.it/public/file/37346936655.pdfIn PDF document text
    • https://davaocarrental.com/images/file/megoluginusikuj.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160db0ce8a97b4---48525560152.pdfIn PDF document text
    • http://shuswapladystriders.ca/userfiles/file/lolopisomit.pdfIn PDF document text
    • https://lentes123.com/aym_image/files/17980555409.pdfIn PDF document text
    • http://hockeydh.com/files/ups/files/vuxepo.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161039ac14203c---tebasesifivavo.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/0ee5ae0b2155c8fa2bf57f67ace3d03c/15429957289.pdfIn PDF document text
    • https://ekransamara.ru/files/zenanafuz.pdfIn PDF document text
    • https://c4ir.ae/wp-content/plugins/super-forms/uploads/php/files/1qd5hbsk78uf7hdhf9qmcamgr7/rekofixa.pdfIn PDF document text
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/kd99oh5go3lvsencjsmfgpu9u5/44508871257.pdfIn PDF document text
    • https://amursvoidom.ru/media/files/68210178739.pdfIn PDF document text
    • http://24hnbc.com/assets/ckfinder/core/connector/php/uploads/files/jirakatewugapu.pdfIn PDF document text
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/fr7i0nn6vjv4la2gbngcb3bkhr/lisotugumikixow.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d2fc765c948---ramorinavodub.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be77546826c---78457756467.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb7bcd89a7---nisonelenidodumoziwanipaj.pdfIn PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/71052028936.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160895207cb26f---nivudusobegegaxek.pdfIn PDF document text
    • https://fotoprint.lv/downloads/file/77818991782.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610a11016058d---fuvebusedaginujimivudosad.pdfIn PDF document text
    • http://gadkowski.pl/repository/filemanager/file/31923159235.pdfIn PDF document text
    • https://limmaginebistrot.com/file/vonutabowewez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=best+exercise+to+lose+side+belly+fatPDF 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_off0000ffff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFFF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011811.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11811 16836 bytes
SHA-256: f191bf72286c8af243f8846cd834072a2be7f651cad8755d18fcb9e9fdca8d77
font_02_sfnt_off000143d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x143D8 10772 bytes
SHA-256: 22209b79843ffbef0da02e511db2d494dfb8885fbe69684ae9efe8d1b21fc94c