Malicious PDF — malware analysis report

Static analysis result for SHA-256 f91c23ef99cb4685…

MALICIOUS

PDF

85.0 KB Created: 2021-07-01 10:57:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e686a70807aff314fe8def5d940477b3 SHA-1: f3e5b27fc21af901430fcd7cb54161ffd858368d SHA-256: f91c23ef99cb4685f3c574d84887529e204d628bfbbb6ce34fba23a1a12aeaba
156 Risk Score

Malware Insights

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

The file is a PDF that contains a link farm pointing to multiple compromised WordPress sites. These sites host other PDF files, indicating a chain of redirection likely designed to obscure the ultimate malicious destination. The ML classifier and ClamAV detection strongly suggest malicious intent, consistent with phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/f66ed1cd5a7cb9d6a76ba78c34e89f56/40813787622.pdf
    • https://m-astar.com/UserFiles/files/jukenuwozuvig.pdf
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/7d3939ba743f8b39058bc883c60178ac/22139160772.pdf
    • https://agrachoff.ru/wp-content/plugins/super-forms/uploads/php/files/f28c1c551118ae7cdbc8e43e0b511c36/32438994032.pdf
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/6c4e96de94cafefc08019b5704af031f/79778636690.pdf
    • http://landpas.pl/upload/file/81870099653.pdf
    • https://lee-trading.tw/archive/upload/files/ridibaju.pdf
    • http://elonsummerstorage.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfae5980bee---kinejenodafizakemeri.pdf
    • https://alakharia.com/public_html/userfiles/file/9167126548.pdf
    • http://lhsclassof68.com/clients/73441/File/72880114159.pdf
    • http://escuelasfutbol8.com/docs/files/zifofizamekodaf.pdf
    • https://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/00f592f4c8f52a89a7566977461e1982/kitononamasuwuvowadi.pdf
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083df02df685---sunubofo.pdf
    • http://cogersquest.com/clients/f/f6/f6194b381802d71b6842d6160e8859b1/File/figetuxojebatogurewapefuw.pdf
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/160a2b2ff8174b---20341859398.pdf
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/40tea8b9fdv8jbbkt1tiubai9v/91579232540.pdf
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160a86cc069dda---tuzikulug.pdf
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/827f8bdk1ge0qoak77ld61mpb3/dubepotetomugedu.pdf
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160808d03bcc9c---legefufogezesi.pdf
    • https://blueridgelightingandcontrols.com/wp-content/plugins/super-forms/uploads/php/files/c2e8c35fa113ae874822cad52edb0096/16774494265.pdf
    • https://grafitpoint.ru/wp-content/plugins/super-forms/uploads/php/files/69a2748e686abc87ec6d20af30ef0384/49982743199.pdf
    • http://allycatering.com/userfiles/60813994163.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=dogs+play+growling
    • 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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e941.bin
f9343b2c414cd97ad6e292cf191bc619b3a9eb3f438da618dbb6238f5ec790dd
pdf-font-stream PDF embedded font (sfnt) at offset 0xE941 17076 bytes
font_01_sfnt_off000115ef.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x115EF 16792 bytes
font_02_sfnt_off00012e06.bin
76b5720de6a5462643b6fb52175e635efb8101c979aaecf5d9cf1f6506509ad6
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E06 10400 bytes