Malicious PDF — malware analysis report

Static analysis result for SHA-256 71cea0ab6635ef61…

MALICIOUS

PDF

75.0 KB Created: 2021-09-05 20:12:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 58c54de7a19a8d00f3e718f0fa35659b SHA-1: 8b358581e5c3c609e4a935ef9a55e2f2ee15e024 SHA-256: 71cea0ab6635ef61816721564ac128affceba1f72cd6c6c16ff4af5260770838
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, which in turn host other PDFs. This suggests a phishing or malware distribution scheme where the initial PDF serves as a lure to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://aquamedia.cn/ckfinder/userfiles/files/fikololazopoxagiwas.pdf In PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075566a9e4fe---niwinejugudodel.pdfIn PDF document text
    • http://aallergy.netlovestories.com/upload/files/lizugezepikinaguk.pdfIn PDF document text
    • https://proxus.nl/file/30824347985.pdfIn PDF document text
    • http://poultech.net/d/files/30327936991.pdfIn PDF document text
    • https://manualismedicina.hu/fileok/file/ruguwititobimobugidivakox.pdfIn PDF document text
    • https://grupo-kayros.com/userfiles/file/20804748181.pdfIn PDF document text
    • http://neodermclinic.com/file_media/file_image/file/91954821108.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1608089baafdc2---14276207102.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e459e49a08---ropaxodabudepura.pdfIn PDF document text
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/5e16ae79befe559507c0044830b6b8c2/dexavo.pdfIn PDF document text
    • http://boeschfamilytravels.com/clients/43210/File/82665578329.pdfIn PDF document text
    • http://backupcenters.com/userfiles/file/fetej.pdfIn PDF document text
    • http://skyline1968.com/clients/74864/File/26963634845.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a403271eea1---17910964082.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160f663c79e00c---14849809838.pdfIn PDF document text
    • https://ngaa.org.au/application/third_party/ckfinder/userfiles/files/sibagap.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160a991aab18e6---62058234992.pdfIn PDF document text
    • https://turkihale.com/userfiles/file/zumukijuluvifitegavejav.pdfIn PDF document text
    • http://teplospectr.ru/images/files/risojasukoxeruxufepo.pdfIn PDF document text
    • http://cpviettin.com/upload/files/50892734157.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/161155124de50c---wefenarexetuxololib.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/a43653ffff8412966d7534cd723184fd/zokusuvomizowixu.pdfIn PDF document text
    • https://myupfield.link/wp-content/plugins/super-forms/uploads/php/files/irne011dapf195vbb7oh20ps7h/vupexexokipogazaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=ford+tourneo+connect+service+manualPDF 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_off0000c45c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC45C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dc6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC6E 16240 bytes
SHA-256: 78fbd8c2ce184d3aa363c9e885f1bda81e6d7bb82bc4fceab9552fd3f91e68ba
font_02_sfnt_off0001057e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1057E 10672 bytes
SHA-256: 134dd091954223c888ea79d681cd80eb63f06b695a3980d2db5891f2b017edb3