Malicious PDF — malware analysis report

Static analysis result for SHA-256 211f940ee6c3e1af…

MALICIOUS

PDF

87.2 KB Created: 2021-10-05 13:17:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0ff222e90a6c95490c7e3bd0b0b2bebc SHA-1: ccbda1c20330a9b0a696fe23c499736ad78d31b6 SHA-256: 211f940ee6c3e1aff63f37e7ffd099e832b87874757bb1573d7076e677f3d3aa
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but serving as a container for the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://krisoc.ru/uplcv?utm_term=roger+ebert+hated+hated+hated PDF link annotation
    • https://ayurmitra.com/files/file/mupunugoguv.pdfIn PDF document text
    • http://taxicityplus.ru/userfiles/file/vejajumuzekufag.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/161496c278dcc6---8315156589.pdfIn PDF document text
    • https://karthikaspices.com/uploads/file/17543115390.pdfIn PDF document text
    • http://cerezolorente.com/files/cerezolorente/_repo/file/17400979579.pdfIn PDF document text
    • http://longchimvac.net/app/webroot/uploads/files/26528529282.pdfIn PDF document text
    • http://bangladeshceramicsociety.com/uploads/editor/files/nakofibenulojenivezixepen.pdfIn PDF document text
    • http://stroykap.com/application/views/stroykap/userfiles/file/30038595740.pdfIn PDF document text
    • https://yptea.com/data/fckeditor/files/vifuferetunole.pdfIn PDF document text
    • https://georeno.ca/userfiles/files/zinimakulobapapasinekafa.pdfIn PDF document text
    • http://platcometals.com/images/file/2661771261.pdfIn PDF document text
    • http://brandiassociati.it/userfiles/file/ritajuvimopasobixo.pdfIn PDF document text
    • http://antifftech.com/uploadfile/file///2021090921483982.pdfIn PDF document text
    • https://singhaniabrothersltd.com/ckeditor/ckfinder/userfiles/files/28797977695.pdfIn PDF document text
    • http://cnfgl.netsociality.com/upload/files/rufis.pdfIn PDF document text
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/1614b3f262c5b2---50791938603.pdfIn PDF document text
    • https://angelsstaff.com/uploads/file/33084487671.pdfIn PDF document text
    • https://xaydungdonggia.com/app/webroot/files/images/pages/files/wixafi.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/feef380c6ee353dfe5d93c83fa7d878e/zugotoxolukaga.pdfIn PDF document text
    • https://sieuthimayphat.com/ckfinder/userfiles/files/pefaxaj.pdfIn PDF document text
    • http://imosa.asia/uploads/files/202110041810189498.pdfIn PDF document text
    • http://schoonhovensvrouwenkoor.nl/ckfinder/userfiles/files/44299318957.pdfIn PDF document text
    • https://deconkhoemanh.com/wp-content/plugins/super-forms/uploads/php/files/f8e77qpcg5ianj5am3s4pavu9v/1039290527.pdfIn PDF document text
    • http://verduciautodemolizioni.it/userfiles/file/12611838225.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_off0000edb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDB3 10304 bytes
SHA-256: c336dfb96936d4d626d92281e82aa905a37f43a6ab68ef59b3fc18398d1d73b0
font_01_sfnt_off000104d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104D5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011ce7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CE7 19076 bytes
SHA-256: 134d93e24ca068203b185dd21c60f510afbb3d4e4cc0fe1ba6d38410c3c84269