Malicious PDF — malware analysis report

Static analysis result for SHA-256 50432c8c9804dbe9…

MALICIOUS

PDF

80.5 KB Created: 2021-08-11 21:06:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: af3709efff44f4dc3725289ba2245bbb SHA-1: b20b986555d0dc8e881ebaed5d81c80157f32c6d SHA-256: 50432c8c9804dbe98faf0931c281dae050fdfc99c773ac130003034274ef9d50
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites hosted on potentially compromised or disposable domains. The embedded URLs and the nature of the heuristics strongly suggest an intent to redirect users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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://laborke.ru/uplcv?utm_term=preescolar+2+mi+album+preescolar+segundo+grado+2019 PDF link annotation
    • http://www.pics4us.de/userfiles/file/susewibiroxupedijoniben.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/d74999oueo6ucisg5njc1tnqr6/nemevi.pdfIn PDF document text
    • http://abwninemile.com/uploads/files/28664374680.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f5e486ee15d---wemutesegeperawefej.pdfIn PDF document text
    • http://bienchidan.org/uploads/files/sezalusejos.pdfIn PDF document text
    • http://rauvuonsach.net/images/uploads/files/76370352484.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202108101047019934.pdfIn PDF document text
    • https://damiel.eu/userfiles/file/59191216607.pdfIn PDF document text
    • https://asiarsolutions.com/userfiles/file/kexisidalopunip.pdfIn PDF document text
    • http://autoset66.ru/admin/ckfinder/userfiles/files/71000549586.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/8br833ltcjmpdpkd19qifc381e/dizipegogesezawajuwuma.pdfIn PDF document text
    • http://hmconcretemixingplant.ru/d/files/95811364358.pdfIn PDF document text
    • https://bda.ch/ckfinder/userfiles/files/joremulovogojetabixila.pdfIn PDF document text
    • https://birudongker.com/contents//files/51733039773.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc657dbd30f---39501561950.pdfIn PDF document text
    • http://groupementpecheduloir.com/ckfinder/userfiles/files/zemudebifaguxufatimokopu.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078078e4426b---tawikibupimuxekurus.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c95bb8d3d0a---32941250685.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16089a97b197cc---13131111516.pdfIn PDF document text
    • https://www.hamburgeriaagricola.com/wp-content/plugins/super-forms/uploads/php/files/hp31ja8iej2jhffnr41aoa6h8i/xupasakupo.pdfIn PDF document text
    • http://alvit-bk.ru/userfiles/file/29337118156.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607011adddb5d---37587367937.pdfIn PDF document text
    • http://whs1963.com/clients/7/75/758a827d59fb1c2827eec60421ffdc22/File/pifiguda.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071f31d574bb---sukedebawavigafo.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_off0000d1cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1CF 11464 bytes
SHA-256: 9a5a9c4c19dc2bc19aeab1c3fe1a7830a6a31cdc8d36f818d1af7a18ef8a7a50
font_01_sfnt_off0000ec81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC81 17580 bytes
SHA-256: fb15cb30c7c3027ed43b366d5c426cc04863b07cbae1500f3e08eea25efc9a8f
font_02_sfnt_off00011945.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11945 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1