Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c8651861c2cb4e6…

MALICIOUS

PDF

83.2 KB Created: 2021-09-19 11:11:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 401392c3337165fb30c610790663d110 SHA-1: 0df117504d3e97b4f0040a6fa1cfa070b9f480b9 SHA-256: 3c8651861c2cb4e664d4c813f1bccd8685f0a40c5c8a75b0a24f7bf13139f499
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to create a network of links for SEO manipulation or to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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.
  • 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://queure.ru/uplcv?utm_term=i+know+what+you+did+last+summer+killer PDF link annotation
    • http://lammensfilip.be/uploads/files/butidigidupi.pdfIn PDF document text
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/5a5b12188a9955b2f598ba48c2ee134a/61176659494.pdfIn PDF document text
    • https://angel-juicer.com/FileData/ckfinder/files/20210915_EA03E08E8D3A9310.pdfIn PDF document text
    • http://www.lircai.com/web/inline/file/59230304116.pdfIn PDF document text
    • http://sevinctekstil.com/resimler/files/18589844921.pdfIn PDF document text
    • http://efuturesthai.com/uploads/file/92863538098.pdfIn PDF document text
    • https://bulgariapools.com/contents/files/33102115103.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/8dl1vi82pq6h0h18c0ggc834t1/25709458782.pdfIn PDF document text
    • http://usefchina.com/uploadfile/file///2021090604305658.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135aebe8ba78---muvumuzutig.pdfIn PDF document text
    • http://resortvillairene.it/userfiles/files/64030952274.pdfIn PDF document text
    • https://bengalroys.com/ckfinder/userfiles/files/wejogivixexa.pdfIn PDF document text
    • http://apple888.vn/luutru/files/vimililunavonuxek.pdfIn PDF document text
    • http://brukbet.com/user_images/file/85427094720.pdfIn PDF document text
    • http://thietbiantoanttk.com/uploads/files/37958265393.pdfIn PDF document text
    • https://konyaalotaksi.com/userfiles/file/fofilezosagodaxafuzi.pdfIn PDF document text
    • http://cafegreenwichvillage.com/uploads/files/19183551357.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/virijonukutevezupakewefi.pdfIn PDF document text
    • https://museuminiaturesbesalu.com/files/77799939536.pdfIn PDF document text
    • https://ksi-system.pl/editorfiles/file/widedurabipolejenepasot.pdfIn PDF document text
    • https://gazeta-msp.pl/user_files/File/67350162021.pdfIn PDF document text
    • https://niboparis.com/upload/fckeditor/file/1632005432_1.pdfIn PDF document text
    • http://119pump.net/d/files/levuvoz.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_off0000ddb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDB2 18248 bytes
SHA-256: 504db559ec34372536393bd512292174cff4ebc489d767998a3e50c5d7f07c76
font_01_sfnt_off00010e05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E05 10856 bytes
SHA-256: 072fc4ba467169a89557dbbbc78bc55d03d8cd46d682285bf78c0556c5b606f3
font_02_sfnt_off000126f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126F7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1