Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f53a3bfec80f0a8…

MALICIOUS

PDF

83.1 KB Created: 2021-09-02 13:28:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f3ed8c7eea4c8ae5ab1c51592e0dd35a SHA-1: 5b5a5a3d75d7cc823e3a2fa426259320ddef9162 SHA-256: 3f53a3bfec80f0a822c1dcd092d6cc853dd9310011f9c3533b1eb44f15359547
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous links pointing to compromised WordPress upload storage and other disposable hosting, suggesting a link farm designed to redirect users. The primary purpose appears to be directing users to potentially malicious sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://szallas-karpatalja.com/upload/kowugekekopopugaz.pdf In PDF document text
    • http://hi-reid-solutions.com/wp-content/plugins/super-forms/uploads/php/files/8770b6b8ed85c38b55559b5e3d89c308/gumadox.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a669f968196---ruzas.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078083a06f0c---tumuxuzukonepaxezudigowe.pdfIn PDF document text
    • http://safiorida.dk/operatori/userfiles/file/68206542811.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/4a9bd6f7dfd9c69f037f34781bb47ffb/2021965585.pdfIn PDF document text
    • http://kooijobs.in/ckfinder/userfiles/files/ziveviponomido.pdfIn PDF document text
    • https://ph2020.org/FCKeditor/file/rafowinugoluteluraxij.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ae1f36d3ac---54283103689.pdfIn PDF document text
    • https://latework.cz/soubory/66610406583.pdfIn PDF document text
    • http://dharmapuridiocese.com/svnprojects/DHD/Source/images/files/23173374097.pdfIn PDF document text
    • http://lawyergz.net/uploadfile/files/57956397454.pdfIn PDF document text
    • https://bamor.org/userfiles/file/jewuvupawibefikadukireto.pdfIn PDF document text
    • http://redigonda.it/userfiles/files/neruxozobumade.pdfIn PDF document text
    • https://skvacations.com/userfiles/file/1394924081.pdfIn PDF document text
    • http://syuncyoku.jp/upload/file/funeve.pdfIn PDF document text
    • http://npi-management.org/ressource/site-image/files/nirogenenip.pdfIn PDF document text
    • http://quaker1960.com/clients/3/34/346d0055920ff30d27c63167e405b0e7/File/mikekuzarenez.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160d2e91ee9959---dosojuwafadowo.pdfIn PDF document text
    • http://granite1962.com/clients/869125/File/kifiralupokojibozedini.pdfIn PDF document text
    • https://boucherienabli.com/uploads/FCK_files/file/suritixu.pdfIn PDF document text
    • https://inoxquochoang.com/app/webroot/files/images/pages/files/55625010940.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d87ecfe2c9d---31888073157.pdfIn PDF document text
    • http://tamker.hu/userfiles/file/xutevedafiz.pdfIn PDF document text
    • http://vinag7furniture.com/app/webroot/files/editor_upload/files/jevimepu.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/be05cbe364870df7245b0515dd130217/25413878638.pdfIn PDF document text
    • http://rymwid-training.com/userfiles/file/wojuxewutarepibapute.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=sydney+university+campus+map+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_off0000ded1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDED1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f6e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6E3 17732 bytes
SHA-256: b5df9aca2d5afd6a8038892174eb4b44a20cc56293b65f4cc48b65e28f916e06
font_02_sfnt_off00012551.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12551 10972 bytes
SHA-256: 1d5ee1eb7e08189eedb61f7f2c8c082424bb3a4c4b1d956667419f06fa214b40