Malicious PDF — malware analysis report

Static analysis result for SHA-256 1531708b3089327d…

MALICIOUS

PDF

96.4 KB Created: 2021-09-20 21:10:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: eedf4e0256a532048b5145dd0e9a8595 SHA-1: 475f8dad7e0917011bfc6f5ff258c4b9ea5e6762 SHA-256: 1531708b3089327d19f48b50f90abf6d3cbd888ebc3efc2c2da084e9195c9860
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable hosting and are part of a link farm, a common tactic for phishing or distributing further malware. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the presence of multiple links to potentially compromised or disposable domains suggests a malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://mikomisushi.com/uploads/files/19037678178.pdf In PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/32881591184.pdfIn PDF document text
    • https://thai-airpark.com/ckfinder/userfiles/files/zirulevegovipabe.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b06d507cfc---rijizafoniwajen.pdfIn PDF document text
    • https://xehowo24h.com/images/ckeditor/files/bamofufeletamopojanawer.pdfIn PDF document text
    • https://www.nhabe.com.vn/ckfinder/userfiles/files/rekojoweparikuruwedupo.pdfIn PDF document text
    • https://machnik.net/ckfinder/userfiles/files/remirulapibevetuzudorero.pdfIn PDF document text
    • http://twsl.mingann.info/upload/ckfinder_temp/files/20210912144805.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/q0sqdnj5tc729q0rfppk73fngc/64296176871.pdfIn PDF document text
    • http://centroolosprato.it/userfiles/files/17223026259.pdfIn PDF document text
    • http://auswallendorf.de/userfiles/file/lafofajefevepenubo.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144ee8e3adda---lovubiramukaru.pdfIn PDF document text
    • http://vasekurzy.cz/userfiles/file/59767464961.pdfIn PDF document text
    • https://jiu-hang.com/upfiles/editor/files/noriretiwo.pdfIn PDF document text
    • http://www.fd.ntou.edu.tw/ckfinder/userfiles/files/24193897192.pdfIn PDF document text
    • https://www.mnogotrop.com/ckfinder/userfiles/files/85865168905.pdfIn PDF document text
    • http://kemnhapkhau.com/upload/files/tosikiderutam.pdfIn PDF document text
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/cbd854776f96c4850f30285cf89699ab/tewexow.pdfIn PDF document text
    • https://airxps.com/userfiles/files/gobej.pdfIn PDF document text
    • https://rafaela-motores.com/userfiles/file/23739799855.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/47023255310.pdfIn PDF document text
    • http://transporteslaplata.com/imagenes_web/file/66779098693.pdfIn PDF document text
    • http://cathugo-catamarans.de/res/wysiwyg/file/kuduvefumetinulodesod.pdfIn PDF document text
    • http://asqcert.net/files/files/potuf.pdfIn PDF document text
    • http://muszempilla.com/files/file/34646860005.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=juegos+que+no+pueden+faltar+en+tu+androidPDF 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_off00010f9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F9A 20160 bytes
SHA-256: 837b2b19a8282ab181dc8af69d5df202ae85ab529d8b0f2dc219ed1098133090
font_01_sfnt_off000142d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142D2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015ae9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15AE9 10912 bytes
SHA-256: 0ae078040d2e06aae34c6aa4958481ac99df8df5a1c07c8903ae317665706fba