Malicious PDF — malware analysis report

Static analysis result for SHA-256 b521afcccfecb11f…

MALICIOUS

PDF

74.6 KB Created: 2021-04-30 20:44:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 3102c4fa20b346f954ddd010454db1cf SHA-1: b0db43faef15348629931f98657e76910d83e902 SHA-256: b521afcccfecb11f5c5a95d4c1ee886e89cc7c887ab8ad1d7eca3163ab41b20a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress upload directories and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create documents for phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/16080ac47a9bde---37665051678.pdf In PDF document text
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/7o1dho0elggs0srfvs5lov2ta2/46009623212.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/babc2efdc41f06c1948e50ce7bc4d425/vapajiraberul.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9700a97a2---7611557483.pdfIn PDF document text
    • https://cal.lighting/wp-content/plugins/super-forms/uploads/php/files/4369c96b51343f5e714fd966bf5d6651/gejukosajobub.pdfIn PDF document text
    • https://evg-prague.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16080a5a269552---33429031910.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073df2bcb249---80124749694.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1606d7bf38c17d---fexigeroliwiwusugima.pdfIn PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/06bb46273756b5a4188c25e9400e8ada/6185749001.pdfIn PDF document text
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/jtq9bt763757lvkt9q95u8q0oa/fiwonederilubupegevix.pdfIn PDF document text
    • https://advantagelic.com/singhania/downloads/file/vobajoxijewujazivo.pdfIn PDF document text
    • https://slaterlighting.com/wp-content/plugins/super-forms/uploads/php/files/479bf83bfbb76385c6b5989112ed1479/sudejapuzef.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606c97a4ec4ef---zixevulufamenufazate.pdfIn PDF document text
    • https://beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/80da2e00ec265188a008ec6dde24a81d/1682301437.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/16074c9087dec3---53360117112.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca3eef092a---regijelafexi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=kai%2527+sa+adc+guide+s8PDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e8cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8CD 5176 bytes
SHA-256: 70abe242578d74a2b9242a77b7841e48c9dbc66f410a9cc23828ea2878461069
font_01_sfnt_off0000fa82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA82 10396 bytes
SHA-256: f5b9ba9afbcdf9454df20520331090f11c4e1675d699d74529ae4e2fdae14df8