Malicious PDF — malware analysis report

Static analysis result for SHA-256 b55d9573aa91776c…

MALICIOUS

PDF

70.3 KB Created: 2021-09-27 12:06:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 2c2c534d5fcd830cc2db793a8d6ddfd5 SHA-1: fd046d166f1172bb5eb51acd8b84845023fae838 SHA-256: b55d9573aa91776c0c4644266ed61e71a6cfe58309db12cfe12d78a95a9e51bb
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on disposable domains or compromised CMS uploads, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The document body is heavily obfuscated and does not provide direct clues, but the heuristic findings point to a malicious link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://rheinmotel.com/userfiles/file/65426790780.pdf In PDF document text
    • http://oppedisanorobertosrl.com/userfiles/files/55577295187.pdfIn PDF document text
    • https://jyapa.com/jhuoyue/uploadfiles/29843530816.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/161303e7ca2dd9---xuginarajapesomeb.pdfIn PDF document text
    • http://npi-management.org/ressource/site-image/files/63451800260.pdfIn PDF document text
    • http://funagamex.vn/PhuongNamGroup/userfiles/files/soboserugal.pdfIn PDF document text
    • https://cnc-ar.ro/files/file/tivabinavoso.pdfIn PDF document text
    • https://iphonerepairservice.nl/app/webroot/files/userfiles/files/65926912227.pdfIn PDF document text
    • http://hanilkwanla.com/uploads/files/92890520938.pdfIn PDF document text
    • http://cngwalk.com/fckeditor/userfiles/image/nivulejeputuvozawotoriru.pdfIn PDF document text
    • http://canhtoanland.com/upload/files/4963353245.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1614e32de25a3d---34425853253.pdfIn PDF document text
    • https://projetounificado.com/uploads/files/17912931305.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f4b021d3a3---18567569445.pdfIn PDF document text
    • http://thankschicken.com/uploads/files/rukulif.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613e7cf6410fe---bexul.pdfIn PDF document text
    • http://jocoseatee.com/userfiles/files/95076466714.pdfIn PDF document text
    • https://keluargamimpi2.com/contents/files/kodabexevidap.pdfIn PDF document text
    • https://www.displaysdirectaustralia.com.au/application/third_party/ckfinder/userfiles/files/tonolaboted.pdfIn PDF document text
    • https://tideandtigers.com/ckfinder/userfiles/files/59821093686.pdfIn PDF document text
    • https://agriplan-rs.com/dados/ckfinder/files/gesefixero.pdfIn PDF document text
    • https://trongtrucsolution.com/uploads/files/41355042335.pdfIn PDF document text
    • http://dent-pro.cz/pic/file/xivezibozuxetibofujufu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=old+yeller+movie+freePDF 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_off0000b004.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB004 17504 bytes
SHA-256: 1a8540233d45c522c54b87ae5d4d610e0e0d0dd877d86b1f8fb21c56c4fabeb6
font_01_sfnt_off0000dd2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD2B 10188 bytes
SHA-256: 63d1ffabfa278a7b77cf34848d84eeb07d6b06b3cdbd3e691be1a069aa3c426f
font_02_sfnt_off0000f3f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1