Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef8134bf80f93fa3…

MALICIOUS

PDF

95.0 KB Created: 2021-06-26 11:38:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8d406ab766a512106568ff137166429f SHA-1: a76127982a4c2b0f0eb1b10296118c51b5d6c4ca SHA-256: ef8134bf80f93fa39a2d7228e1d1719419df98ed8144af1a2891d55586a8ee4f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, embedding numerous URLs that point to compromised WordPress sites and other potentially disposable hosting, suggesting a phishing or SEO manipulation scheme. The presence of multiple external URIs and link farm heuristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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 https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/a4c3aca0ea31034a772050a4311cc0ef/nomasuromoxafonofileb.pdf
    • http://nanumed.ro/uploads/files/werolimegetuw.pdf
    • https://thesaddlebank.com/wp-content/plugins/super-forms/uploads/php/files/46ei6jn1tlhh8klhf98tc55edu/62594372930.pdf
    • http://gyobel.itpublic/file/xozexitezodivabinuv.pdf
    • http://aiswaryamatrimonials.com/fck_uploads/file/lajuvimetuxonukolojebif.pdf
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160aab31de9321---42656047725.pdf
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607484c8884da---3292178373.pdf
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/35ad775d5aa52efe83e1e13a713ccdc2/buwifer.pdf
    • http://flygarfield.net/userfiles/file/43271324093.pdf
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a71b72cfc0a---viwonagofezewuz.pdf
    • https://belloverde.net/emailer/file/vunovon.pdf
    • http://batiment-tunisie.com/userfiles/file/65257800018.pdf
    • http://apsons.eu/files/file/87046109335.pdf
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/2d707b759c3077da33093eac8364bc51/90130385900.pdf
    • http://rosswellbulldogs.com/clients/b/be/bee1e50a814ad4ba40998340b8964064/File/44243252347.pdf
    • http://446888.top/userfiles/file/mukogogaxatiguf.pdf
    • http://szalkasszorutacskok.hu/app/webroot/files/content/files/wukuwimetubonulopa.pdf
    • http://bclgrouptt.com/userfiles/file/tebewatosef.pdf
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/eca405f616970fc8f808588b1a79eb43/78205908899.pdf
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f273f39316---93000416860.pdf
    • http://seashoresilverlabradors.com/clients/4/48/482fd9669fb3260065120a60ccac5e48/File/73733605786.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a0329989a0f---lewazotokiv.pdf
    • http://pizzeria-millemiglia.de/app/webroot/img/editor/file/bopegoxap.pdf
    • https://hssipm.com/wp-content/plugins/super-forms/uploads/php/files/8502b9a085dbbd0d0d6e0cf228c20432/joladaribimusebu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=is+there+going+to+be+outer+banks+season+two
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010ef8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10EF8 16792 bytes
font_01_sfnt_off0001270f.bin
1ec70ebd7daeff803cd91bbe61e534a293e88f85d703f9f8ce54c3e8825bb3bc
pdf-font-stream PDF embedded font (sfnt) at offset 0x1270F 10708 bytes
font_02_sfnt_off00013faf.bin
cd985aa932d588128a86950ab4b1c42911221b3d531379534b78b726be6bb229
pdf-font-stream PDF embedded font (sfnt) at offset 0x13FAF 17836 bytes