Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4d8e1bad3621cca…

MALICIOUS

PDF

91.5 KB Created: 2021-07-19 14:21:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 09c95e82797e9c3e6be87af0c0f5cd6f SHA-1: 0dca094b0bc673bba2789ab7b851bb6ed7195f34 SHA-256: e4d8e1bad3621cca700e98d3f1967184c689d8ac33b0060365b957b8f052e87e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated a high probability of maliciousness. Several heuristics indicate the PDF is a link farm, with many URLs pointing to compromised WordPress upload directories, suggesting it's used to host or distribute malicious content. The document body is heavily obfuscated and unreadable, but the presence of embedded URLs and the link farm structure strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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 https://okazdedziecko.pl/_files/Media/file/43282402760.pdf In PDF document text
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b273903ee2---pisowexigepefebawagojaraf.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d7ee54f0dc9---9913793509.pdfIn PDF document text
    • http://franzoesischebulldoggen.eu/userfiles/file/wulurifuw.pdfIn PDF document text
    • http://soflocops.org/clients/83264/File/13934110217.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/e9953af36dc2067def3cac8a97c636c5/tovitusago.pdfIn PDF document text
    • https://landi-bg.com/images/file/18420145062.pdfIn PDF document text
    • http://blpest.com/UserFiles/file/kosofadesunotetuj.pdfIn PDF document text
    • http://muszempilla.com/files/file/subulamapota.pdfIn PDF document text
    • http://7166867.ru/ckfinder/userfiles/files/wuledibun.pdfIn PDF document text
    • http://ehomeforeclosure.org/images/file/xawun.pdfIn PDF document text
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/f010cfc32c0d84fcd1efbb849b34e30f/kuvuwinidesifonap.pdfIn PDF document text
    • http://detikakdeti.ru/img/file/29507593546.pdfIn PDF document text
    • http://enjoyisagenix.com/ckfinder/userfiles/files/kitiz.pdfIn PDF document text
    • https://seedomoretravel.com/files/files/17801798780.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/160872d77b417e---43956095892.pdfIn PDF document text
    • http://qunjl.com/userfiles/files/gubudiwijudelu.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/50786e82a7a4e592a6cd74c423b16918/lizulosigiburujujol.pdfIn PDF document text
    • http://bycongroup.com/UserFiles/file/46498683063.pdfIn PDF document text
    • https://elsadaulte.com/ckfinder/userfiles/files/padovitaligoguri.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a090600fcc3---donosikugubamuvemarole.pdfIn PDF document text
    • http://doyen.cc/images/upload/File/38365519999.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=waterfall+in+leitrimPDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b58e52a54f2---kitusapaxupu.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_off00010369.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10369 17416 bytes
SHA-256: c3ab0c5c7e3095a889374393ba12b1211356a293306c22f1a20679d027012a80
font_01_sfnt_off00013112.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13112 10080 bytes
SHA-256: 33b0ecb310ecdcb6eee3444e335f59993cbd62eb98f1bc6f1e8527789e4d2496
font_02_sfnt_off00014772.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14772 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1