Malicious PDF — malware analysis report

Static analysis result for SHA-256 2353155945ade41e…

MALICIOUS

PDF

79.6 KB Created: 2021-09-03 13:43:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: b849ed6566f545b6cfc543d81e53e22d SHA-1: 6ee12df9d22daaa9d87189446c85db92a6a969f8 SHA-256: 2353155945ade41e4151a2ed621e8a76fc4637af92eb59992779b03a6afad61b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised CMS platforms or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the presence of embedded URLs and the heuristic findings suggest the document is part of a phishing or malware distribution campaign, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://aulacvn.com/upload/fck/file/412865183.pdf In PDF document text
    • http://becucci.it/userfiles/files/fukopivepekig.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160767f679a651---82734939801.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083a7895647b---lufapaduwo.pdfIn PDF document text
    • http://biznesfishki.ru/files/userfiles/files/66051887757.pdfIn PDF document text
    • http://tz5168.com/uploadfile/image/2021/08/06/file/20210806_183724_102.pdfIn PDF document text
    • http://honyi.tw/ckfinder/userfiles/file/22666763807.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160a5d4234e63a---bekaserawivugal.pdfIn PDF document text
    • http://maybaobidinhdinh.com/upload/files/97982328251.pdfIn PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/j5i7ke36kdb1ciqggmbbomeuk2/xajip.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/56f3cac26413c2ab953a4bb0a20174e4/gidanatugupuz.pdfIn PDF document text
    • http://www.atccs3.it/atccs3/fckeditor/editor/ckfinder/userfiles/files/96884243425.pdfIn PDF document text
    • http://transportdiverse.com/uploads/files/16077062853.pdfIn PDF document text
    • https://daotaolaixesontay.com/uploads/file/93270265611.pdfIn PDF document text
    • http://theprojectmanagement.guru/cote_dor_import/admin/ckfinder/userfiles/files/57232208573.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/l0kdj0ktfv41gehljvfr37j90o/27990287913.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/nvcqbq3se6e8cpa3fue2hd166p/sixexowevetatazogujujam.pdfIn PDF document text
    • https://fzclicks.com/demo/files/editor/file/lomadedidixoderol.pdfIn PDF document text
    • http://naturalfurnish.com/userfiles/file/sejanutefawazowo.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/d4ed97fa1fb9564a6a7828f228b374e2/mekodogu.pdfIn PDF document text
    • https://tinhhoaxanh.vn/userfiles/file/liguderego.pdfIn PDF document text
    • http://spc1991.com/ckfinder/userfiles/files/fufonef.pdfIn PDF document text
    • https://vico-immobilien.com/ckfinder/userfiles/files/40518601447.pdfIn PDF document text
    • http://vdtonline.vn/static/uploads/editor/files/besakupuvewubufuxewagim.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=nelson+biology+grade+12+textbook+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_off0000cff1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFF1 11272 bytes
SHA-256: 779d74a107f87ff9fdde246a03417085a8a4f8a76303a2be051c6f108b8eb947
font_01_sfnt_off0000ea3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA3E 17704 bytes
SHA-256: c1a1942e53271c9b818543880dc649a1d97997c6a5fa8affd22c6e7cc3c5c632
font_02_sfnt_off00011863.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11863 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1