Malicious PDF — malware analysis report

Static analysis result for SHA-256 af4ec1154cfdb363…

MALICIOUS

PDF

82.8 KB Created: 2021-07-06 20:35:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: ae71fa7e58b70f3fa70b125bb998a143 SHA-1: a7c95c39026b1e43493405d607efcc973414ce81 SHA-256: af4ec1154cfdb363cbf2db3ca24b514fb5df1883dbfb79d226288c57612bd15f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it's a link farm pointing to compromised websites. The PDF contains numerous embedded URLs, many of which are hosted on potentially compromised CMS platforms, suggesting a phishing or malware distribution attempt. No scripts were extracted, but the presence of numerous external links strongly suggests the document's purpose is to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/6f474e639fafa50270946e822c5f3aec/31832784704.pdf In PDF document text
    • http://bhhangkhong.com/upload/images/files/bapobumiwu.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c48c2793edb---vovowepopafi.pdfIn PDF document text
    • http://primaria-ciocirlia.ro/media/file/pexolakeganuxusoxagajiko.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607544dc2dfff---fagewesalobitavodexis.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/6qqe6nncvgro48eotjkj492r94/potut.pdfIn PDF document text
    • https://incasur.org/temp//files/werubedexenow.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/wekanuvapomegufen.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/p264phfagkg4ti1to630rg4sjc/tutefezamanarira.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/44159575474.pdfIn PDF document text
    • http://dhf-china.com/d/files/dapolurokofovibumoguzesok.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16083450a9731c---xufepowube.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/7e51c30603bfb063bc52baf9efb1cc29/65869047505.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608a980c5e15d---nozilepikutolafubo.pdfIn PDF document text
    • http://daechienglishpark.com/ckfinder/userfiles/files/65944189257.pdfIn PDF document text
    • http://cleanyachts.it/writable/public/userfiles/file/47289639097.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/7irq5scfd6g5ii09mp40cjtrt5/72374620581.pdfIn PDF document text
    • http://seamacros.com/upload/file/beximanofasuzag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=library+collection+development+policy+templatePDF 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_off0000e316.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE316 10784 bytes
SHA-256: 22f2895c9f6ae2ff8cde01acfd2d1a1504f0f935f4b3c34c14e4197423da5fa1
font_01_sfnt_off0000fbb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBB6 16256 bytes
SHA-256: 31242bf6bccbabbe3acf051bf936a66bbfaff34efdcd4ffb7b5e01f5b8173e66
font_02_sfnt_off000125ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1