Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a331364f0ea8799…

MALICIOUS

PDF

77.9 KB Created: 2021-06-20 16:09:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 0be1d1f7985e50f1715f106b42153295 SHA-1: fa17c3771cfec0f6c14f27fa776c65a1f3515c30 SHA-256: 8a331364f0ea8799753345eeb8d62387a63489d97cb8b07c242b80fc8ed28f74
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites hosting other PDF files, suggesting a link farm or redirection mechanism. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

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://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160c660a3e2567---xomodipefapukot.pdf In PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/16077d0afb9007---27181914309.pdfIn PDF document text
    • https://abandassociates.com/ckfinder/userfiles/files/30472597338.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/9ab35426131196ba53d42f6ea5159a82/38028547914.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606efdd3bb572---pevuwamifesokoj.pdfIn PDF document text
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/2b4efb683def3ad6d5afa9bd89ab4665/61107996093.pdfIn PDF document text
    • http://cityhighclassof77.com/clients/9/9e/9ea685038b5a197d2022a69b8c6b162a/File/mesokanu.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083832ac7f02---20378534077.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160918c2307516---bigijimemutigos.pdfIn PDF document text
    • https://dansobentre.net/uploads/file/pupemurujekebesugezofuj.pdfIn PDF document text
    • http://abimobiliare.pl/pliki/File/56147962625.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7a6b2e43db---96897289363.pdfIn PDF document text
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/160947f6863f51---48054340512.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160ac5932f1da2---rubegawoseni.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608a50d5151d7---52536526915.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160887826d8ba1---6041673815.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c72f17b073b---vixugeraxelivisoni.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/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=genetics+grade+12+notes+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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f1ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1CE 5508 bytes
SHA-256: 21c2e302ca46f716c10314d1b9451c6470448fa016afa09b6cdeb3a5464bce38
font_01_sfnt_off000104a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104A2 10764 bytes
SHA-256: f53fd8756425a570e781619f4666b7078028f28f4c5694942c111cf519ebfaf9