Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8a6af5cf5503013…

MALICIOUS

PDF

115.1 KB Created: 2021-07-22 11:38:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 85293c920bf238a9cad9f169d019e10b SHA-1: 476df2ad7719461af23c8de23bad07c5a2c692f6 SHA-256: a8a6af5cf550301390f563b62ab8515bf51d3d78f3778e2aaa62d5704c4a13ab
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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 http://eros-arena-reutlingen.de/eros/userfiles/file/83705794292.pdf In PDF document text
    • https://thokhoavietnam.com/upload/files/xuwuxakiz.pdfIn PDF document text
    • https://dixietemporarystorage.com/wp-content/plugins/super-forms/uploads/php/files/e4565cc256d772d4d2d140dd85708a41/rexigadolavase.pdfIn PDF document text
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/3ff708cd2e51e4835cf32948bea41d4e/bejurus.pdfIn PDF document text
    • https://andrejc.si/files/file/14192308526.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/27a48c5ea20f5e9459cc06a3125d6ebe/makofesurakeja.pdfIn PDF document text
    • https://guapa2.com/admin/fck/file/67973191284.pdfIn PDF document text
    • http://automotiveenergy.cz/userfiles/file/silomemoviriwe.pdfIn PDF document text
    • https://udruga-invalida.hr/files/tojejarenukir.pdfIn PDF document text
    • https://cbdc.co/uploads/ckfinder/userfiles/files/madunovulibudelo.pdfIn PDF document text
    • http://linkingpeople.info/userfiles/file/69592897336.pdfIn PDF document text
    • http://sweden2020reunion.com/clients/e/e2/e2375cbe45a1e08e95d3a39ca41e84e3/File/kinawowejax.pdfIn PDF document text
    • http://mintaialuminum.com/d/files/4649853865.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/g45ga6uufehdqhvn5i0t6bsrdg/81249656092.pdfIn PDF document text
    • http://myarrahnu.com/mo_images/files/galomoxajaf.pdfIn PDF document text
    • http://mgocsm.in/userfiles/file/kiditagujedudogifudiret.pdfIn PDF document text
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/75115ac6feb6ea122632b97c6e3a2c0c/37178584176.pdfIn PDF document text
    • https://pasarangroup1.com/contents//files/22784182789.pdfIn PDF document text
    • http://hanasushipickup.com/uploads/files/lirunaxutazole.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be2a652ad91---21945130054.pdfIn PDF document text
    • https://sbufficio.it/file/79883828907.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078b11555eb3---98685970610.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=diagnostic+meaning+in+tamilPDF 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_off000161da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x161DA 10476 bytes
SHA-256: d75d356fdd6ab61ad35505689a97279ca253202aad5cc700d78a11f94839300b
font_01_sfnt_off000179a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x179A1 17268 bytes
SHA-256: d96d787a15354d4f455163c47fc0f509304e783ff68d0898d27855046f35fa78
font_02_sfnt_off0001a670.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A670 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1