Malicious PDF — malware analysis report

Static analysis result for SHA-256 420a0d44ea22a0c4…

MALICIOUS

PDF

83.4 KB Created: 2021-06-14 16:31:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 48a48b9249f2755912fb57c39d418673 SHA-1: 8e4417f81f6cfc5edfbd3abcf9d722a717dd7f18 SHA-256: 420a0d44ea22a0c498a23bbc7adae5ec503c29070ee16ffec32c0e9490655896
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

This PDF document employs a social engineering lure, instructing the user to install a browser extension or update to view its content. The document contains numerous links to external sites, many hosted on compromised WordPress installations, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for credential harvesting or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://krisoc.ru/uplcv?utm_term=sonic+the+hedgehog+2+mod+apk
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a69eaa7bd8a---50504815247.pdf
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/04cd68302406331339556d579ddf97eb/34141044823.pdf
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/16092259e251ad---napajujifoxilizibefawuf.pdf
    • http://www.siscbolivia.com/admin/uploaded/fck/file/gufufutopupumugatemo.pdf
    • http://kartywspomnien.pl/uploads/assets/file/6526212380.pdf
    • https://haltia.mx/sii/ckfinder/userfiles/files/wetepozotozup.pdf
    • http://casaperferiesantamariagoretti.com/writable/public/userfiles/file/66378451201.pdf
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/7bb3b176a030afaeebeb4a62b250f4c2/93090455282.pdf
    • https://agrimal.pl/userfiles/file/83926653589.pdf
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c508a98f8c3---juwolokuziz.pdf
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/a0d386ac6b36aa5a5f16884bea607d6e/gozivazavazozugupegovebab.pdf
    • https://castilloexterior.org/ckfinder/userfiles/files/naxelowel.pdf
    • http://dentish.ru/ckfinder/userfiles/files/26445287415.pdf
    • http://n-production.com/upload/fckeditor/file/pamitanetevu.pdf
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/ead10d80cd06dfb27870b89564f66672/puvenigozazuse.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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
    • http://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00012160.bin
b3b5a50700cbc36cbe48e9e7183f629030e8da4d968f4abd46fdc17908b6fe87
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x12160 18700 bytes
font_00_sfnt_off0000e68f.bin
fa74f6f1211d36ef96ebff868aae78ac0f2b354306b097a428850f9008bf976b
pdf-font-stream PDF embedded font (sfnt) at offset 0xE68F 5480 bytes
font_01_sfnt_off0000f912.bin
3433b7fa390af21f6183cc393bb14ac64c5fed9d6e8720fa23fbe94fc3267ae5
pdf-font-stream PDF embedded font (sfnt) at offset 0xF912 12316 bytes