Malicious PDF — malware analysis report

Static analysis result for SHA-256 f16d258784577f17…

MALICIOUS

PDF

80.9 KB Created: 2021-09-19 14:17:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 3420f29ee54b256afd1a72dd3c053421 SHA-1: fd648a90635e4b762b54244e05147ffea0d4c4f3 SHA-256: f16d258784577f17db1cc5095fc2caa135b8502553fdfb0e0bcbf9d547d1951d
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm designed to obscure the final destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery through these links. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content to analyze.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://mintedimages.com/ckfinder/userfiles/files/sopitirugotape.pdf In PDF document text
    • http://explosivedevices.ru/media/file/45262984832.pdfIn PDF document text
    • http://www.jasfec.com/imgs/uploads/98261934654.pdfIn PDF document text
    • https://kmkmekanik.com/upload/ckfinder/files/lawazileselumarazudapuwi.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/df5df7c94e1d7e344d1bab4b556d1a1d/6630865346.pdfIn PDF document text
    • http://indago-rovigo.it/userfiles/files/67474163201.pdfIn PDF document text
    • https://bvphcn.bdata.vn/upload/files/xobar.pdfIn PDF document text
    • http://sinice-rasy.cz/files/file/dadalezikuluzi.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed5eb9afec---10909333159.pdfIn PDF document text
    • http://www.solarwindependence.com/ckfinder/userfiles/files/7841493201.pdfIn PDF document text
    • http://timocomputer.cz/files/file/8475703211.pdfIn PDF document text
    • https://www.lsv-wittlage.de/ckfinder/userfiles/files/26456863028.pdfIn PDF document text
    • https://www.igescanada.com/ckfinder/userfiles/files/6108493866.pdfIn PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/jugirazisof.pdfIn PDF document text
    • http://nhagiatxanh.com/public/default/ckeditor/files/bawigesuriruwotun.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/161410d6b7ec39---berif.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614024eadcab8---wadigojudug.pdfIn PDF document text
    • http://www.bluefashion.cz/ckfinder/userfiles/files/vuposudilafosowexuvope.pdfIn PDF document text
    • https://alsultantrading.ae/userfiles/files/84723446759.pdfIn PDF document text
    • http://bidwoodmachine.com/d/files/13389291463.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/33ea9ecfe48f34c3f8fc609ef434a5e5/xaxudufaxowosu.pdfIn PDF document text
    • http://zjbfjt.com/upload/files/65618046320.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=minecraft+the+survival+collection+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_off0000d778.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD778 10876 bytes
SHA-256: e8255819c93a566fdeb57881679912b6a87fe9ffda7a9ef8cb386f7a5b6150c8
font_01_sfnt_off0000f091.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF091 17332 bytes
SHA-256: 7fbdb45e172b26eeccccb7a662066a3645a1d8eee734890c42ed51c663f5bc56
font_02_sfnt_off00011dd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1