Malicious PDF — malware analysis report

Static analysis result for SHA-256 19b31a9cdb554de5…

MALICIOUS

PDF

85.9 KB Created: 2021-06-30 11:00:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 75e11a7e38f12403f5b6ed6be50a1162 SHA-1: d0c5fc49dfa866cad3b663035ecc9231fbbb484d SHA-256: 19b31a9cdb554de5f8f9f688a1f2e29560d49fb753d4e644a6558a570854b17e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous links pointing to compromised WordPress sites, which in turn host other PDF files. This structure strongly suggests a link farm designed to distribute malicious content or conduct phishing. The ML classifier and ClamAV detection confirm the malicious nature of the file, indicating it is likely a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/ca2f3ba1bf0f647116523e22ad56d5c3/makugopil.pdf In PDF document text
    • http://begemot-rus.com/uploadfiles/file/2021061907134473499.pdfIn PDF document text
    • http://nw-line.ru/generic/uploaded/sibotuzavixotisu.pdfIn PDF document text
    • http://ivepe-elearning.gr/assets/UserFiles/mainHome/file/66172136565.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c4b6e9c53fd---bawosatofowizevokotatej.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/4d06d9056eae64a0a28bb34d2ce677dc/83127705057.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/b4d65874ea186b1e22f57fdbe12784ee/lebupododelivipituvawezex.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ff4e62b483---3997769436.pdfIn PDF document text
    • http://hugslock.com/app/webroot/img/files/seborasawexozesutej.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096d49d93fd6---fovobol.pdfIn PDF document text
    • https://ajitcoatings.com/uploads/ruwezenasifexazudidixi.pdfIn PDF document text
    • http://stroisvias.ru/userfiles/file/94737376886.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/cfbadc918ab15ac6c4679d704992682f/xaluru.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/abe20f423edf10a456d41b9028577b45/911415659.pdfIn PDF document text
    • http://lideparts.com/userfiles/file/1622140469.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078ba5c44c27---jibaluxosavapuwejiz.pdfIn PDF document text
    • https://soudurelauziere.com/upload/editor/file/mutanuleruditilewojujok.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c8b180e38da---bujorilanumekerovifuju.pdfIn PDF document text
    • http://nnrhc.com/clients/9/98/980d61ede38c9a35fe3396fb65651545/File/vakotesuta.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160758b6ca6795---buvevadawalobesu.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/db318ba071baf75c72e7282c63b7f2c6/20355409743.pdfIn PDF document text
    • https://www.picmephotoboothhire.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16079bece44b74---zuziremovu.pdfIn PDF document text
    • https://samowar.ch/upload/file/tepidu.pdfIn PDF document text
    • http://thetsaban3watnuea.com/UserFiles/file/9703110309.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=what+suv+has+manual+transmissionPDF 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_off0000edd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD6 17188 bytes
SHA-256: db4c1e4f5abf687b8817ef323e63e0fcd1a0de3b4154dca35c47953495ab595d
font_01_sfnt_off00011aa0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AA0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000132b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132B7 10400 bytes
SHA-256: 8bc69901274654121f0beefbe31c1391899a4c714a9bbfdc068b318d8f37ddbc