Malicious PDF — malware analysis report

Static analysis result for SHA-256 026a5143160bf5a8…

MALICIOUS

PDF

98.5 KB Created: 2021-07-04 06:52:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 12970218800704aefe62114880d5ad20 SHA-1: 4d9492c539e1d16df5705c65e7f83ba9380135bb SHA-256: 026a5143160bf5a88f797005e57430e61c20a6596c4e6083e5b730dd4681454b
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 compromised websites or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and numerous URLs suggest an attempt to redirect users to potentially harmful content or for SEO manipulation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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://acgroupenterprise.com/userfiles/file/2791074547.pdf In PDF document text
    • http://schroniskoorzechowce.pl/ckfinder/userfiles/files/xukavutizajexij.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a8bfc45b68f---40547553368.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160887dad670c4---zajuforup.pdfIn PDF document text
    • https://kopari.hu/files/file/kolowewufolabipiguvulu.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1607263d4c2cea---17923622481.pdfIn PDF document text
    • https://traveletrust.com/basefile/traveletrustcom/files/nawodita.pdfIn PDF document text
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/31ac6261f27c4f62b0c3975e977c9bfd/xojokowelejagevejir.pdfIn PDF document text
    • http://skipjackpoke.com/ckfinder/userfiles/files/52754927653.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbd85f6711b---tifal.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/31294768289.pdfIn PDF document text
    • https://vidolamerica.org/wp-content/plugins/super-forms/uploads/php/files/bc5ce13142a879e087fac7e5c5514993/ruzolafuvenikegezesonib.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/ea1dc716eaf0320465bdc1c8cc8cb147/16185377488.pdfIn PDF document text
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160a2d0d9ac503---13958895828.pdfIn PDF document text
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/t083q6kbh84i2fcd2vj4813634/pezorajikulekabilov.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1607b86b94f89e---soreneguxivafenox.pdfIn PDF document text
    • http://pappteam.hu/userfiles/file/xujix.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd06d2e85a---wovulo.pdfIn PDF document text
    • http://studiotrusso.it/userfiles/files/92711146352.pdfIn PDF document text
    • https://muzeumkonstancina.pl/attachments/file/kajesubub.pdfIn PDF document text
    • http://booklandbooks.com/userfiles/file/buwenufe.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608f5c70f367d---ronuzuperitadepanaj.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/ghq2jpedu2voinq64s53ovj8q1/napolepetebisavulu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=clinical+microbiology+and+infectious+diseases+pdfPDF 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_off00011e12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E12 11348 bytes
SHA-256: be48f3e4ca1219a6b7e5402c1eb8c630108cd47814541e1ec05e8c6d1b0d9f8a
font_01_sfnt_off00013860.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13860 16896 bytes
SHA-256: 4c7796fdfaa9bd78a4894730ba09b0cf3d90648b00b6123c32562fc4e40529a2
font_02_sfnt_off0001645b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1645B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1