Malicious PDF — malware analysis report

Static analysis result for SHA-256 d86113811cd2a1bc…

MALICIOUS

PDF

101.3 KB Created: 2021-09-02 20:15:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 591d573eb9bbe79b2bd32d47625f3477 SHA-1: 54f6d502da6597c83b93a0a98ebfb41c0e4084fb SHA-256: d86113811cd2a1bcc6a925a03979a546cfaaadf220430098160c11cf0e45fd1e
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to various domains, many of which appear to be compromised or disposable hosting, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or delivering a secondary payload. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9803

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://cinstech-inspect-survey.com/fckeditor_userfiles/file/ninipewiwolalo.pdf In PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/qi8l3mn2h6clei9gp2fs3lutq9/noberuk.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/bifizifulosarafokeda.pdfIn PDF document text
    • https://istocdukkan.com/userfiles/files/safaj.pdfIn PDF document text
    • https://detectiveoffice.net/userfiles/file/bireturifugefiterejinewis.pdfIn PDF document text
    • https://engineeredrepinc.com/wp-content/plugins/super-forms/uploads/php/files/de1c24a800b7db3006843319aec17b27/11938133550.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/ce42a3d557bbf9d402ab24e0525cec7e/tipelotalobitajuk.pdfIn PDF document text
    • http://ultraljud.nu/bild/files/80485743952.pdfIn PDF document text
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082860cbc203---xubudejabetunitafixow.pdfIn PDF document text
    • http://naturallabs.de/userfiles/file/dogerebexepaki.pdfIn PDF document text
    • https://www.prshots.com/ckfinder/userfiles/files/doselovekazowudogemade.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab6b5a0408---zotoson.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16126ba53c1d90---439698129.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b52868e2af7---23801153323.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/8f7955590d7369025aefd2948287d225/wogose.pdfIn PDF document text
    • http://jan-fotografie.nl/upload/files/8164061579.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/87nka6hgn2754mprb6q5gkn7o0/69744728067.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607afa759b418---lepisawep.pdfIn PDF document text
    • http://md-servicios.com/userfiles/file/67450167994.pdfIn PDF document text
    • https://juhaszautovill.hu/userfiles/file/58978678903.pdfIn PDF document text
    • https://iwistw.com/upload/files/denabeketuj.pdfIn PDF document text
    • http://appartenvue.net/appart/upload/images/kikutepafa.pdfIn PDF document text
    • https://egf.tw/test2/images/file/92272439446.pdfIn PDF document text
    • http://sicilyontable.it/userfiles/files/93617596359.pdfIn PDF document text
    • http://kadh.kr/bobod/upload/file/ruvamolemitutapu.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/160728d88b7eb9---tagogelizum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=quistes+de+entamoeba+histolytica+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_off000123d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123D1 19192 bytes
SHA-256: 1e4deb74f7c07ce1866708987053c813ab199f82edcfe37ea8944cd379e825bc
font_01_sfnt_off00015577.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15577 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016d8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16D8E 11200 bytes
SHA-256: a82e5264bc6a0fb1b5749eced23e69c531e17c32d49fc27dba41bb3a2682a1de