Malicious PDF — malware analysis report

Static analysis result for SHA-256 88bfb3d1c323ed0f…

MALICIOUS

PDF

81.0 KB Created: 2021-09-02 16:08:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 3c033eb06c240c1fa01455f0e6e58460 SHA-1: 768993e89597226c5347366b796c173e998263b5 SHA-256: 88bfb3d1c323ed0f1afb6a3bf90689a31f0475be3e79cc7463de98caa99c8b92
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF was flagged by multiple heuristics, including a ML classifier and ClamAV, indicating malicious content. The 'SE_CLICKFIX' heuristic specifically points to a social engineering attack that instructs the user to press Win+R or paste a command into a terminal, likely to download and execute a secondary payload. Numerous URLs were extracted, many pointing to PDF files hosted on compromised websites, suggesting a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • ClickFix social engineering attack high SE_CLICKFIX
    Document instructs the user to press Win+R or paste a command into a terminal — consistent with ClickFix attacks that bypass macro restrictions by tricking users into running malicious commands directly
  • 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://vaitinhdien.com/app/webroot/upload/files/tumadoxut.pdf In PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c7feac7d13---28737512201.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/4b85bf86ff671db8499ef02e398bc713/denubafogiriwuti.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/elnauqmd6mtdb6do8bakhi3svs/25658686981.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b58d9e43458---57818120759.pdfIn PDF document text
    • http://firegallery.ru/img/upload/29427682821.pdfIn PDF document text
    • http://modero.vn/upload/files/sovilulajozu.pdfIn PDF document text
    • https://banktapeunadana.com/tapeunadana/bank2/admin/userfiles/file/76777671810.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609af7254dc3a---19780561709.pdfIn PDF document text
    • http://cdn.eagle.mn/uploads/userfiles/files/33735028686.pdfIn PDF document text
    • http://esthebel.de/userfiles/file/72724135615.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/47sif40uau0j0bdoce31er2538/ratabujaviwuvokigigafine.pdfIn PDF document text
    • https://dienlanhbachkhoa.info/upload/files/43172775522.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160d8a0dddaa18---lafafuzejimog.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b2fcb1efab8---55934160556.pdfIn PDF document text
    • http://zsdbiopharm.com/upload/files/mojababonomilojogilowages.pdfIn PDF document text
    • http://xn--dlek-5qa.com/admin/UserFiles/file/pagujisirusedesevideni.pdfIn PDF document text
    • http://yousefmaktabi.com/ckfinder/userfiles/files/49879720846.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/gf5l4rqj6pvvfi55sl3iaplt37/51152699281.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/16128466ef1c05---ladiz.pdfIn PDF document text
    • http://virtuozi.ru/sites/all/sites/virtuozi.ru/files/11817379971.pdfIn PDF document text
    • https://www.marvistasales.com/wp-content/plugins/super-forms/uploads/php/files/c1f81e443cc89f41ea23f2e8507bd748/88742302844.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=ppt+not+saving+as+pdfPDF 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_off0000d62a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD62A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE3C 18408 bytes
SHA-256: 0586fe69aa097ad1b92e9ffb9946f36fb678c7c54f134b9c2087384004316221
font_02_sfnt_off00011e84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E84 10464 bytes
SHA-256: 69f3c3643f34f473942199aab88e63dba38a4e7331baf22f6ab5c1ba83a68dd4

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