Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6331bd138813663…

MALICIOUS

PDF

93.6 KB Created: 2021-06-05 17:44:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f6ec8e782fb901ebc9a81285606fbcbb SHA-1: 33d00557679e59512f34a37cdabc0aed3e0b2ad8 SHA-256: a6331bd1388136630a092689770b14e6b484935f50068ee5bf1cc9edd0c3ca3a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links pointing to compromised WordPress sites, suggesting it's part of a link farm designed to distribute malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded URLs and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further support this, indicating the document's primary purpose is to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://coretry.ru/uplcv?utm_term=miraculous+ladybug+season+2+episode+11+en+francais
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/8d2igkakqlb02u7g2k4hapq2bu/33323538637.pdf
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160794352d45fe---60852856451.pdf
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160810d6b00fd3---16680805747.pdf
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b5f63c627f8---70641315072.pdf
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/5a715384bdf6039f477b0d5a37f8b380/zoreminesulujukusulu.pdf
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c934c1a858---papefogagilaripagajikox.pdf
    • http://sacoorhealth.pt/site/upload/file/97713200993.pdf
    • http://china-zub.ru/userfiles/file/zural.pdf
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/b6f04a82ad28b1d7f24c38e05f5dc4cd/1278231971.pdf
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/af0817713f877d3db86f459ffac75961/wonezopexu.pdf
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/feb0104ef4bd066bc3171b4089943194/tufusara.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/f6a42a9fef45c0018c095a41b0f63533/2017253037.pdf
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b655e5ee14d---41080740100.pdf
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607e20ca877b4---88315498655.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/84b323d51d54f3b3a3f197d14a6e5224/zikeximuliwubuzux.pdf
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16072b0a240cc1---zupoloberunuviwex.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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012a2a.bin
b6896ef16acf605267c478a5f0f025ef970474a58675e65be93ec016c4f4e5bb
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A2A 5752 bytes
font_01_sfnt_off00013de5.bin
9d0515ae9f7ddfb73747bd0ec9e861abc39d74179f40fa7ec5c8fadcf0f00591
pdf-font-stream PDF embedded font (sfnt) at offset 0x13DE5 13304 bytes