Malicious PDF — malware analysis report

Static analysis result for SHA-256 c81676aeb53c3b1f…

MALICIOUS

PDF

176.7 KB Created: 2021-07-29 21:36:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 178887b38f1bafb75752af29f0f35b75 SHA-1: 2608dab80204dd6d14c944b8da77351e98f6385f SHA-256: c81676aeb53c3b1fe1115feab3250e15b098d81cdb704fe79f91ad123c6841f4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised WordPress sites, indicating a link farm designed to obscure the final destination. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • 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.
  • 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://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608746231071f---95520945473.pdf In PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/snupo4pcqv1l9msmbfgm7dsoi5/46537593833.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609928c443498---boluxetotisedega.pdfIn PDF document text
    • https://sokolzgierz.pl/web/uploads/files/lagawezekozorowu.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080a5cf39ee5---mozozexetilupekize.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c003735da1---danojisofabubosawilano.pdfIn PDF document text
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/3d3f3fdc0c60d47644003c9d9d91c31e/xavob.pdfIn PDF document text
    • http://amdind.com/userfiles/file/60986289950.pdfIn PDF document text
    • https://maydangson.com/vietkiendo/upload/file/pufawudaxuxusafi.pdfIn PDF document text
    • https://maviet.vn/upload/files/losuralemogupilareti.pdfIn PDF document text
    • http://fujiya-la.com/uploads/files/wonekiterivofijarejiwu.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c5718682a40---26934256124.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/23847282540.pdfIn PDF document text
    • https://bahispesinde.com/gnc/veri/_files/98837166473.pdfIn PDF document text
    • https://mmszke.hu/files/file/52976186655.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a31c4039bfe---winosotejiv.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a6c52ce66c---zabuperedaveruluviloz.pdfIn PDF document text
    • http://gostinica-domodedovo.ru/files/52934160126.pdfIn PDF document text
    • https://liniagdanskzydowo.pl/files/vomegeruwikafadi.pdfIn PDF document text
    • http://ncabhsa.com/clients/875427/File/46213348071.pdfIn PDF document text
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bcefb4224f---fuxebewadabakugo.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b8a7c69f35a---18116536896.pdfIn PDF document text
    • https://thejinglelab.com/wp-content/plugins/super-forms/uploads/php/files/he22nrp76c7j4bfe0kni7fjrf8/81096725638.pdfIn PDF document text
    • http://automozg.by/upload/editor/files/71673371814.pdfIn PDF document text
    • https://ajitcoatings.com/uploads/wesexij.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=leccion+de+escuela+sabatica+cuarto+trimestre+2019+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_off00024a7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x24A7D 11440 bytes
SHA-256: 84a0bbf7b2879d83b7654d5182222f468bf0e2eb2c3f82e3755f4e27be9fc7be
font_01_sfnt_off0002655f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2655F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00027d71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x27D71 20836 bytes
SHA-256: 9304d25b92af30228a71465a16857cf8510ce34a4b9fa13d0965f1d4278ea08b