Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c3ca11036254ce8…

MALICIOUS

PDF

68.2 KB Created: 2021-06-24 02:29:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 8b2d6a2c0aba1d403897c155ccc502d7 SHA-1: 8e83da7f82dad9f1b5093e5e25e8d442ca472aea SHA-256: 4c3ca11036254ce85d095f7aae5cbf50b27857cbd2c906b9f4f77daf1ad57c57
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload directories and other disposable hosting sites. These links likely serve as a distribution point for further malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://ndt-tl.ru/upload/file/womokabunuko.pdf In PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/aa76uut14f839pi1sb8mmfc54v/4292053539.pdfIn PDF document text
    • http://congtydaihai.com/upload/files/gugunowivofipaxetud.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160793b05c5093---gokinujawavunivunag.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16090b8cd2c5a9---30595838538.pdfIn PDF document text
    • http://premium-t.info/files/files/73418074266.pdfIn PDF document text
    • http://lushexperiences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160768f8fa0d14---tomodulez.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd87a517690---movajaperajotofavav.pdfIn PDF document text
    • https://anfauglir.com/images/file/zupavesopaje.pdfIn PDF document text
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608132480f1a7---2795850436.pdfIn PDF document text
    • https://harrisitalia.it/uploads/file/lufosokodopekogij.pdfIn PDF document text
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/4897bd2ccd06170cb119a70b2227d2c8/50162228473.pdfIn PDF document text
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/vlkn8atrnrt2avqpmg1f30q1kv/25661054021.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/057621bbf4ab0b4354340b7382c80278/46004481886.pdfIn PDF document text
    • http://mrbossamktown.com/uploads/files/venudawerebaxuvurebugez.pdfIn PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/57810321431.pdfIn PDF document text
    • https://praward.tw/wp-content/plugins/super-forms/uploads/php/files/b99dde2a88f341d292a361116beb22df/pagoxoz.pdfIn PDF document text
    • https://daaeportrett.no/upload/file/2107244976.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160bc62d09177b---viveko.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=heartware+lvad+user+manualPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cf73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF73 5084 bytes
SHA-256: a599c612f7532cfba1640b3f57b01d4754c39007efdcb80d1c3acac546c30dab
font_01_sfnt_off0000e0bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0BC 10340 bytes
SHA-256: 89eb9a93b2aa5efcc3c4e5d3a38c455a03f8ae3f3f734774150c26935f339245