Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5cc874a199e3461…

MALICIOUS

PDF

79.2 KB Created: 2021-08-20 11:16:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b1a8545bc384919ed58ad7845a21e33d SHA-1: 908cdace4111b50ddc3cb7259183ebaeed881fd7 SHA-256: b5cc874a199e3461f72ee460e0f1f4dcde0e1ee4041f6227bc28614afa0c5eab
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of external links, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm or SEO poisoning tactic. The ML classifier strongly indicates maliciousness. While no scripts were explicitly extracted, the nature of the links and the heuristic firings suggest the document is designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://ketchas.ru/uplcv?utm_term=diccionario+de+arquitectura+y+urbanismo+mario+camacho+cardona+pdf PDF link annotation
    • https://osikovo.eu/webroot/img/content/files/momavawozikagisewozubural.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/95f5a1c860fde7b824a569385ee59147/nalisitikobemuzijaveron.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a2ced05564f---fupuwufaxatukub.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/fb651e1a40e4bb20f4f93d08b0d4c6d3/15208176502.pdfIn PDF document text
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/29175060255.pdfIn PDF document text
    • http://www.rannatennis.ee/data/upfiles/files/25805328049.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160861cbf59f16---dimofixat.pdfIn PDF document text
    • http://abc-tel.ru/data/File/fomeritorumujogexodisas.pdfIn PDF document text
    • http://cokhibaosang.com/media/ftp/file/99192129716.pdfIn PDF document text
    • https://kisikana.hr/UserFiles/files/sufininamamejub.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1611ad531d840a---tanoxakolunaperek.pdfIn PDF document text
    • https://b2cexpressdemo.com/userfiles/file/59279146599.pdfIn PDF document text
    • https://bikinibody.be/wp-content/plugins/super-forms/uploads/php/files/8sq7m3ldbjqubh9avgmteuqvjm/89383868023.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1611ed4ee4f4d9---xiguxudonenulilopujevemot.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608a0d5cb4a99---gasudekul.pdfIn PDF document text
    • http://goref.ru/files/file/6741138045.pdfIn PDF document text
    • https://widepolymers.com/userfiles/file/jivevafepixiwazusonu.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/653565c8f70b92ac47a58184914cd142/jakokofo.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/4b070e3cde644f5de722e544ffae05cd/74645457393.pdfIn PDF document text
    • https://mehreganimaging.com/images/upload/files/noramagatud.pdfIn PDF document text
    • http://medica-brno.com/files/93745331497.pdfIn PDF document text
    • http://hzzxtl.com/UploadFile/file/20210716022201175.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1606eaf8dbefa3---97566110578.pdfIn PDF document text
    • https://www.gasserbush.com/wp-content/plugins/super-forms/uploads/php/files/387583b2d9710147d4047671fdfd434a/kipupabofigevoruguvu.pdfIn PDF document text
    • 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_off0000cac9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAC9 11340 bytes
SHA-256: 54ee55a6825797a439d21ecd2e8f49369a04cc34e76dddd311f138f0e2cbf824
font_01_sfnt_off0000e4ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fcfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCFC 18544 bytes
SHA-256: d32f43abad58b407c6349f42c8f3db6012e94de9642f9ddb9639528e430fc1c4