Malicious PDF — malware analysis report

Static analysis result for SHA-256 18b07fbcfc9d6782…

MALICIOUS

PDF

85.8 KB Created: 2021-07-17 11:46:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 8a717731c5492852a4a2bf0b05776a3a SHA-1: bba182d2b51db5a8ce7570a81977aa5af0951747 SHA-256: 18b07fbcfc9d67828988029da66c47386e05336419a8da2779dde18b61e9c4e1
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 links, many of which point to other PDF files hosted on various domains. Several heuristics indicate that these links are part of a link farm, potentially hosted on compromised CMS uploads. The ML classifier strongly flagged this PDF as malicious, suggesting it's designed to manipulate search engine rankings or distribute further malicious content through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://skyzoan.com/cake/beta/userfiles/file/bidasuvawo.pdf In PDF document text
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/krru701hcrsmviapgivdqevvd3/tajaziditame.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/funanagofo.pdfIn PDF document text
    • http://www.majbrno.cz/uploads/files/pofuda.pdfIn PDF document text
    • http://xn--365-pn7mwb654m2qn.com/ckupload/files/zojakezezojetep.pdfIn PDF document text
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/7c197b0b7ec20c557b75bcc720c13c87/fowurasijolurifa.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/rlis1o82s778l3lcontrj8vp4u/49978508143.pdfIn PDF document text
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1608c71ad87c75---wibizenaxol.pdfIn PDF document text
    • https://yocarbroker.com/upload/ckfinder/files/sexigipolowubufazexijepil.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/1tjc036cfj2jh4tpcjcddacaqe/53694459252.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16091e0349efba---somaja.pdfIn PDF document text
    • http://clair-environnement.eu/catalogue_dynamique/file/72138574090.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2455a1fea---kerudixusadoboxufatigav.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160e20179ae160---davuxegasasikugotunexem.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16093ea1110c0e---31733800789.pdfIn PDF document text
    • http://sunarfactory.com/userfiles/files/xokaj.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094c3a3bd31b---63150663164.pdfIn PDF document text
    • https://btcauction.vn/hinhanh/file/92827124671.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/0e7c2933aeeb68d77cd840bad2b0b8bc/33566330147.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160bb83d6d629e---69521683966.pdfIn PDF document text
    • https://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/051ace8de7f225e2ad2f315abb417b30/25794521851.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/5513151445.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606fad7164a0a---makovuwumisazidunutezituk.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=campo+ocular+frontalPDF 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_off0000eca8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECA8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000104ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104BA 17580 bytes
SHA-256: eacfff4a81cba581d01d35417f62d73aeb6edc571eaa83909536e7b9f8360148
font_02_sfnt_off0001311f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1311F 10380 bytes
SHA-256: 822e67b148d476af9bf1a49b7df0278c3fc3582fc47edb6f0dac01559096184f