Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf6d8752967077cc…

MALICIOUS

PDF

82.2 KB Created: 2021-09-05 03:45:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 87c0b9f348a04a9c62e5ca58487a63e2 SHA-1: 92bc79709e2258101562f0a348b54d0a815ff7df SHA-256: bf6d8752967077cc9fc2989b763a3ce4132fd0976334684d242ca7f84bd66451
96 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to various websites, many of which appear to be compromised or disposable hosting. The ML classifier strongly indicates maliciousness, and the link farm structure suggests an attempt to manipulate search engine results or redirect users to malicious content. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://vibanghanoi.com/uploads/files/57722930646.pdf In PDF document text
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609838d1e0f25---28298072283.pdfIn PDF document text
    • http://gazosilikatnn.ru/uploads/files/pagesugesuxelusis.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/8812959cb281834e39c06df910d195ba/lewalebal.pdfIn PDF document text
    • http://phukhoabacninh.com/images/files/kajiravesojutenomizutozi.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099bfa2d00fe---89733839152.pdfIn PDF document text
    • https://sabresources.com/FCKuploads/file/16370642992.pdfIn PDF document text
    • http://studioarchperissinotto.eu/userfiles/files/57230216519.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099fe83a931b---zerasoninuneteja.pdfIn PDF document text
    • https://www.alapan.org/fckimages/file/15134533637.pdfIn PDF document text
    • http://wx-bm.cn/upload/ckimg/files/202108280451034682.pdfIn PDF document text
    • http://ampletrekking.com/userfiles/file/10615608305.pdfIn PDF document text
    • http://ciccioinpentola.com/userfiles/files/losasovidigomoxodo.pdfIn PDF document text
    • http://controlsystemco.com/cache/fck_files/file/6348165603.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/739vl68tukk03to284soc74cj3/43178525206.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/160e8e1cfb9991---fenajederifidoti.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/9848e6df2022614edd41e524b61936ea/8335268205.pdfIn PDF document text
    • http://amidoux-peintures.com/ckfinder/userfiles/files/lorixosi.pdfIn PDF document text
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606f473952077---25880853393.pdfIn PDF document text
    • http://integrotech.eu/zdjecia/file/genasijuko.pdfIn PDF document text
    • http://studiotravenzolo.it/userfiles/files/91568077944.pdfIn PDF document text
    • http://zhengfutz.com/v15/Upload/file/2021813513337651.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/c0d8ad73b22c5af0ffeb0097ba790260/52776209935.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/8c5fd5fad6ef9e512497c0642e66954c/26267878216.pdfIn PDF document text
    • http://www.kickcommerce.com/userfiles/file/67437174170.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=hernia+inguinal+pdf+scieloPDF 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_off0000df61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF61 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f778.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF778 10788 bytes
SHA-256: 9b2d5927de2f217c55410a510123695ee70ae31a2754bf263a6dd28ffaec5362
font_02_sfnt_off00011020.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11020 16168 bytes
SHA-256: 877b6ad30f29d80cac0360cbc5bedff2bc20142046e70daad8a44951f800c853