Malicious PDF — malware analysis report

Static analysis result for SHA-256 f754fb5905ca539a…

MALICIOUS

PDF

125.4 KB Created: 2021-09-01 07:25:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 5805fe4adeca46f39dcd7a1d1891a703 SHA-1: 482d2271c47acbef1f9fc964779cd584e4b386a3 SHA-256: f754fb5905ca539af9e4b580f7021adc9cc68500bbcd0d9367ae1394401a1a64
96 Risk Score

Malware Insights

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

The PDF contains a large number of external URIs and link farm heuristics, indicating it's designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and numerous links suggest it may be used to distribute malware or lead users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

Heuristics 5

  • 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://nsck-cykelmotion.dk/userfiles/file/48330675945.pdf In PDF document text
    • http://benedictinoselrosal.org/ckfinder/userfiles/files/romoxofugifugajolera.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/9625b52f46205e9d3fef234cc5528ebc/19580375412.pdfIn PDF document text
    • http://www.allatpatikapecs.hu/images/file/wodadalukorojolavugoxew.pdfIn PDF document text
    • https://alexandrapanayotou.com/web/images/static/file/penunifejamezo.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/e73104423c7d8d04b6ff424c492867e9/93320651482.pdfIn PDF document text
    • http://sriagasthiyarastro.com/FCKeditor/userfiles/file/rajepefexufuresoki.pdfIn PDF document text
    • http://ksklinika.ru/ckfinder/userfiles/files/xevodu.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607a0a4b1f21c---78869075962.pdfIn PDF document text
    • https://blugarden.eu/file/kozevutatenozuxugojarin.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/1cdd5c81558e42320fd5b02ec503948d/ririvevosilikase.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aadf0580c73---wizaf.pdfIn PDF document text
    • http://shsclassof1959.com/clients/a/a7/a7a82b2a6025f7fafce5d77be70bf845/File/dusimafet.pdfIn PDF document text
    • http://usmleworkout.com/files/file/lunutu.pdfIn PDF document text
    • https://zzwgjx.com/d/files/28022692620.pdfIn PDF document text
    • https://equantumconsulting.com/files/files/79206642625.pdfIn PDF document text
    • https://odlingfamily.com/userfiles/file/wasesa.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607f597a030e0---72716903678.pdfIn PDF document text
    • http://nbkhjc.com/uploads/202107/file/210726162859395980ce99ungybv4l.pdfIn PDF document text
    • http://geoodwierty.pl/files/file/68587805287.pdfIn PDF document text
    • https://my-natural-style.net/upload/files/xasuderozopudewuwuzirog.pdfIn PDF document text
    • https://cursosgratuitosonline.es/wp-content/plugins/super-forms/uploads/php/files/6enmuq8ch71d6rmeng3pg00kak/gubekodufoniraweroletak.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f18794582e---salufulopoji.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160727934033df---nazawuturoxovadu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=harvest+moon+back+to+nature+guidePDF 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_off0001848f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1848F 11056 bytes
SHA-256: a7281b0cf590f58aac1de030b79c532667b909160543f6e61e429044ab4dab5d
font_01_sfnt_off00019e16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19E16 18832 bytes
SHA-256: 511d013d788e636c73d56a37a3dc7b30f0a23948a93abbad8145e9ba32e54e11
font_02_sfnt_off0001cff9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1CFF9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1