Malicious PDF — malware analysis report

Static analysis result for SHA-256 683b4652fc150c8f…

MALICIOUS

PDF

85.4 KB Created: 2021-09-02 04:46:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 8a4c481a8e2f7b9963ce10b281f0e518 SHA-1: f73ebf46f4542b66e9ea1614f0dcd537f95e8d6e SHA-256: 683b4652fc150c8fdeea9b991d4776bc1c2da931029e902e965b360c7154b10f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, and it contains embedded JavaScript. It also functions as a link farm, directing users to multiple external URLs hosted on compromised or disposable domains. The presence of JavaScript suggests an attempt to execute malicious code, likely to download further payloads or redirect users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://krisoc.ru/uplcv?utm_term=castlevania+anniversary+collection PDF link annotation
    • http://gramercygrand.ru/files/file/81712483767.pdfIn PDF document text
    • http://faradtvandor.hu/picture/userfiles/file/maxudowagalufozosajam.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/xevuwepir.pdfIn PDF document text
    • http://propertiesforrent.com/userfiles/file///dowubiguxegalategobumike.pdfIn PDF document text
    • https://patidarpalanpur.com/web/k/main_admin/ckfinder/userfiles/files/9864231609.pdfIn PDF document text
    • http://josephfellerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/47942254980.pdfIn PDF document text
    • http://brmhn.com/userfiles/file/20210629074240_o3legm.pdfIn PDF document text
    • http://riccaassociati.eu/userfiles/files/28109650021.pdfIn PDF document text
    • https://finances-canada.com/wp-content/plugins/super-forms/uploads/php/files/fded6f15ce3c34b8033af57bc321da60/vodakokexu.pdfIn PDF document text
    • https://consurs.ro/ckfinder/userfiles/files/bojukomepibumotomo.pdfIn PDF document text
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/e8fa2f3fdfe46a9b21e5d410f23857b5/fisajuwasokuduvo.pdfIn PDF document text
    • https://xpress2.eu/ckfinder/userfiles/files/75953149599.pdfIn PDF document text
    • http://alpha-cp.com/userfiles/file/83950779581.pdfIn PDF document text
    • http://tantos.jp/js/upload/files/nakarigeku.pdfIn PDF document text
    • http://prosquash.by/data/19569980281.pdfIn PDF document text
    • https://thewaves.net/wp-content/plugins/super-forms/uploads/php/files/j0sllf88qk2oemv9rd6nqjllpt/dejigu.pdfIn PDF document text
    • https://ecoretras.com/file/vixujulowedosumekeb.pdfIn PDF document text
    • https://airbays.com/userfiles/file/leradajivedik.pdfIn PDF document text
    • http://geodavidepini.it/userfiles/files/poditomekozixev.pdfIn PDF document text
    • https://hkparkkonutlari.com/image/files/miwiluperebo.pdfIn PDF document text
    • http://studiospazioambiente.it/userfiles/files/retesegetamobonif.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/8baad162c079454982b4c1a92cb635ce/64704199049.pdfIn PDF document text
    • http://siciny.pl/userfiles/file/vofudemibexerisokovini.pdfIn PDF document text
    • http://starlightcelebrates.org/clients/4/43/43e9139217482d7666ce300faf566241/File/6953203411.pdfIn 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://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_off0000e6ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6AB 18820 bytes
SHA-256: 24f605de60cee6efae72013ffe5c9b255080f4a6c659664c76214015e774b844
font_01_sfnt_off000117cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117CC 10432 bytes
SHA-256: 0c6c03457b5c6df9b671330ab29070d108fe46a610e2bfc8d4f7e00ebe5fd1ff
font_02_sfnt_off00012faa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FAA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1