Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6a5fb5c1f2df5e5…

MALICIOUS

PDF

76.0 KB Created: 2021-09-01 17:09:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 88b776c93f08ac7f8a46dd85320b34df SHA-1: 20e85cf23db694b7206ef4f781fdd9ecbd118d21 SHA-256: f6a5fb5c1f2df5e5c3ead608920358ecbefec0020f5464911c50e27bac1cd470
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 http://apexibd.com/uploads/fck_uploads/file/92069079944.pdf In PDF document text
    • http://cohensevents.com/clients/74638/File/tizixuro.pdfIn PDF document text
    • http://bezagsecurity.cz/userfiles/96558301089.pdfIn PDF document text
    • http://oasis-inwaste.asia/files/file/66866743337.pdfIn PDF document text
    • http://capmar.eu/userfiles/file/26128897572.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/kotifekuxebasetoxomuno.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210510010239.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/652c2d99128e80813a1bfd4c087c4693/41875110849.pdfIn PDF document text
    • http://ks-system.co.uk/ckfinder/userfiles/files/21780315447.pdfIn PDF document text
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/1ecf69988718c5d24ae9ad94fa5d8b5c/78601520093.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/8004235366.pdfIn PDF document text
    • http://www.florentmaussion.net/userfiles/File/midunapozarosovotu.pdfIn PDF document text
    • http://turskazka.ru/ckfinder/userfiles/files/27093921651.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/16078285fb5858---rabevafufegolu.pdfIn PDF document text
    • https://esportenerd.com/app/webroot/ckfinder/userfiles/files/zujifap.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ba670eda3ea---84779118853.pdfIn PDF document text
    • http://kryotherapie.net/neu/userfiles/file/povesaxaxonupevoruzora.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/7c2d1564d2ae0013bbbd382ae784b327/573351624.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/47b23e7a5ba0de523f47b7c193048e15/pudukijupuzogapowasaxof.pdfIn PDF document text
    • http://old.bgk-meshkova.com/ckeditor/ckfinder/userfiles/files/malaxowupix.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/c8270f0f630c32dbdd4bbc4fda2b8943/82330159360.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a028762e6e1---5017128178.pdfIn PDF document text
    • http://closehorses.com/userfiles/file/11835985608.pdfIn PDF document text
    • http://photo-preiss.com/upload_files/files/199209124.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=wedding+venues+with+lodgingPDF 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_off0000c679.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC679 10512 bytes
SHA-256: 569719aeb0982375f21d7e1ae3d200600d04a3ff5a6e3cadfe738cf64f0089ec
font_01_sfnt_off0000de23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE23 17156 bytes
SHA-256: 66f494fd9dacb35cabad6cf029f71a057778eefaa631a9dab18e4c8a0055fca6
font_02_sfnt_off000109aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1