Malicious PDF — malware analysis report

Static analysis result for SHA-256 f81a0758683a6e90…

MALICIOUS

PDF

76.5 KB Created: 2021-06-24 21:35:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: f344da430c9405fcaf9b2222e7622f6f SHA-1: 6bec96fbaee0d2f0c9d330c67305910fe7831a80 SHA-256: f81a0758683a6e90eb8e07e44f2c029e62eac60706a8dc7f1874c6cb283ebc66
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm or SEO poisoning attempt. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were extracted, the PDF structure and URL patterns are consistent with attempts to redirect users to malicious content.

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://www.alex-vasilkov.ru/images/wisdom/file/wuropux.pdf In PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3aaddeeb45---xumadokidofibu.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/160743bfa3925b---towatemajasewonakozujo.pdfIn PDF document text
    • http://begemot-rus.com/uploadfiles/file/2021051416333873499.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/0fcb46bc875276777d4d608d9f9a2279/lofogisopajamusege.pdfIn PDF document text
    • http://timnhanhonline.net/upload/files/39250407044.pdfIn PDF document text
    • https://baobihungphu.com/media/ftp/file/78555712450.pdfIn PDF document text
    • https://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/15f6e490b8b3e5d6f89622e197fa840e/32956690595.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/eiib9sgei0ad2ma00rsrlmgeqt/96111584852.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/zutawenut.pdfIn PDF document text
    • https://samsungdvm.net/upload/ckfinder/files/totefejozetokunalunani.pdfIn PDF document text
    • https://digireg.cn/upload/34691528408.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/29780374098.pdfIn PDF document text
    • https://samowar.ch/upload/file/83621079931.pdfIn PDF document text
    • http://flightshop.jp/images/blog//file/10704666126.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/dd957e043767d79e7505914ea3b9ac42/60065504672.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/f6cf2896667c38f074f6db81fbeb7ca8/5312566548.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/texan.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=gta+vice+city+iso+file+download+for+ppssppPDF 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_off0000ece8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECE8 5432 bytes
SHA-256: fec3b474debf89113d88cd1749420c42d39c875c339e4163fc4a712c4492f4ec
font_01_sfnt_off0000ff97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF97 10928 bytes
SHA-256: cdefb837a04e167315c5fe122c1264f774ff9a7be79bb72f9893c84773094e06