Malicious PDF — malware analysis report

Static analysis result for SHA-256 f81d4714e423c10d…

MALICIOUS

PDF

94.2 KB Created: 2021-09-12 14:53:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-22
MD5: 2667507f89b0ba97f4ccb9378af2d4f6 SHA-1: f110e22410995211bb4f78532e4aa15b88823ccd SHA-256: f81d4714e423c10d43b7904f00863a515748b0aa290fe2f55ae75264fca372e7
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

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://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613c64d416f8a---gokegonulevugeja.pdf In PDF document text
    • http://contelex.it/userfiles/files/ritamizebobadowuzofuz.pdfIn PDF document text
    • https://nusamulticentralestari.com/Uploads/userfiles/files/xekesaziwilivenut.pdfIn PDF document text
    • http://naasschoolofmotoring.com/fckeditor/userfiles/file/31043190379.pdfIn PDF document text
    • http://tidomusica.com/uploads/files/202109072252006596.pdfIn PDF document text
    • https://abzesolar.com/uploads/files/24248073792.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613813011a3f7---sumupodezowapogiledosapo.pdfIn PDF document text
    • http://shop-cartuning.pl/userfiles/file/visafugidam.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/43431046234.pdfIn PDF document text
    • http://dnt-mayak.ru/content/File/nozaxezotezakizevepu.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/fced6a1d2a01bf1c0641233135cbaff8/vetubamam.pdfIn PDF document text
    • http://siciny.eu/userfiles/file/juvaluf.pdfIn PDF document text
    • http://ghinelliarchitettura.it/userfiles/files/neruv.pdfIn PDF document text
    • http://uni-farm.pl/ckfinder/userfiles/files/7700767042.pdfIn PDF document text
    • http://residencelesaline.it/userfiles/files/71188919215.pdfIn PDF document text
    • http://pathtojanna.com/userfiles/files/19792907344.pdfIn PDF document text
    • https://lifesmart.lifesmart.ro/ckfinder/userfiles/files/53149211318.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/16137b45d2ebee---kevovemexonipofomatuguzot.pdfIn PDF document text
    • https://greenlandpark.com/uploads/files/34744923155.pdfIn PDF document text
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/0a8d80116bfa5c49d3dd92cfe6b6f17b/rugoneputifuwa.pdfIn PDF document text
    • http://viviapalermo.com/userfiles/files/xasami.pdfIn PDF document text
    • http://xn----itbbfrdrdbd4bgy6gi.xn--p1ai/webroot/files/files/9732002602.pdfIn PDF document text
    • http://koopmankennedyfeller.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/66087617582.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=retro+games+emulator+androidPDF 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_off00010bef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BEF 10736 bytes
SHA-256: 2710dddcd59f743a4d270aed95bb9ba03d4c792dcb3398b865522e532c2a5f7d
font_01_sfnt_off00012461.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12461 17912 bytes
SHA-256: 573c4068bb8af10fefd3424bda29ccd7af5d633f4e185f9c6aaff228f32fda9e
font_02_sfnt_off000152a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x152A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1