Malicious PDF — malware analysis report

Static analysis result for SHA-256 43bd1250672813b3…

MALICIOUS

PDF

91.2 KB Created: 2021-09-01 21:47:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 9e44ea07552ef0532a0b620766e22303 SHA-1: bdfc4e4a049cb601b6a475e8dfba12a6fc0d28b3 SHA-256: 43bd1250672813b37a1705af6693068891e415fa8b357c7c09418a9bc6670786
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The file's structure as a link farm suggests an attempt to direct users to malicious content or exploit kits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://lexcochoralsoc.org/demo/lccs/beta/userfiles/files/29308421816.pdf In PDF document text
    • http://osc-pribor.ru/products_pictures/file/zuvuwa.pdfIn PDF document text
    • http://www.physedu.in/newsite/userfiles/files/sivujutinawepedog.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e41b3121304---62156067633.pdfIn PDF document text
    • http://dailymaytrogiang.com/userfiles/files/8566574938.pdfIn PDF document text
    • https://ymvii.com/admin/upload/files/36298240485.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210813/file/16288228259514.pdfIn PDF document text
    • http://magooferta.pl/uploads/fck/file/zunowomiv.pdfIn PDF document text
    • http://gemculture.com/userfiles/file/wepadotiriga.pdfIn PDF document text
    • https://postelezmasivu-plzen.cz/ckfinder/userfiles/files/novenufurobojibozenunojam.pdfIn PDF document text
    • https://llibreriaha.com/img/events/file/20044432300.pdfIn PDF document text
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/mapagifabulivirogi.pdfIn PDF document text
    • http://xenangheli.vn/public/files/80228282303.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095ff2b069cf---kalegikafedomuv.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608c946b232e6---migusagodexanowun.pdfIn PDF document text
    • http://www.optimizecost.com/admin/ficheros_fckedit_subidos/raxexeximuj.pdfIn PDF document text
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160ad051c3f8bc---63882240263.pdfIn PDF document text
    • http://jjmcp.jp/userfiles/Image/file/4575782651.pdfIn PDF document text
    • https://triosms.com/userfiles/file/169676858.pdfIn PDF document text
    • http://bigband-ulm.de/userfiles/files/dijiwobekujovabawegoja.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608f904d9f66c---63920479431.pdfIn PDF document text
    • http://wittymall.com/multimedia/userfiles/file/46132113140.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=i+was+made+for+another+worldPDF 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_off00010389.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10389 17000 bytes
SHA-256: 19437f6015f42d84b6cac120142c58d2c1344227b021ce1a0e1853040461be72
font_01_sfnt_off00012f87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F87 10564 bytes
SHA-256: f41e1040fb65810c88a59498c9973319d2b33b760a8a0154021d0aee1b8cd018
font_02_sfnt_off00014779.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14779 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1