Malicious PDF — malware analysis report

Static analysis result for SHA-256 84680c7fe9c236e5…

MALICIOUS

PDF

82.0 KB Created: 2021-08-16 08:33:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6b10d0f7d619b8dddfc128b7e5864632 SHA-1: 40bb0883e90ef2662c0a0a2e8c5585f8277ecc84 SHA-256: 84680c7fe9c236e54f08f9b614c8bd463fa178458dcd09f1f9bafa327deecec5
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of links, many pointing to compromised CMS upload directories, indicating it functions as a link farm. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external URIs supports the conclusion that this document is intended to redirect users to potentially harmful sites. No scripts were extracted, and the document body was unreadable, so the exact nature of the final payload remains unknown.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://allamericannursing.com/userfiles/file/16229839164.pdf In PDF document text
    • https://glowskincare.net/wp-content/plugins/super-forms/uploads/php/files/e99b57eff3bd579f45683337e86e1dd7/pinobesupiteg.pdfIn PDF document text
    • http://abwmechanicsville.com/uploads/files/poxuninesedatote.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ad679fd8e13---50377153102.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a1f44abd2f---34751354579.pdfIn PDF document text
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/jpcjiq0nf9dm0lehr5nfjg0t7c/nexuxakisowimarevatu.pdfIn PDF document text
    • https://ficsllc.com/wp-content/plugins/super-forms/uploads/php/files/g8pul94i1gl5tb7qbkv9avfjku/davojow.pdfIn PDF document text
    • http://bugaboo-buffalo.eu/UserFiles/File/fogumolejepu.pdfIn PDF document text
    • http://dinobajka.pl/Upload/file/6147552003.pdfIn PDF document text
    • http://abnicum.com/files/file/vesidukaloviguseremik.pdfIn PDF document text
    • http://kaowei.tw/image/files/20210529_083158.pdfIn PDF document text
    • http://bio86.fr/fichiers/11296498350.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a71f725feaa---livipepebovilafuku.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16103c46de19cf---90944385651.pdfIn PDF document text
    • https://innotek.vn/uploads/news_file/74700368059.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/160948db819154---tejuxabebitake.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/5ec5caf3fd347e6fd1fc94c18ef20d5d/25812120276.pdfIn PDF document text
    • https://xo-sound.ru/userfiles/file/60071040774.pdfIn PDF document text
    • http://tuanayapim.com/rsm/files/rabonawejoxev.pdfIn PDF document text
    • http://an-ocn.ru/ckfinder/userfiles/files/16090875008.pdfIn PDF document text
    • https://eccdc.org/application/webroot/userfiles/file/zozusobezufoba.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=the+daniel+plan+textbooksPDF 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_off0000dd10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD10 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f522.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF522 17204 bytes
SHA-256: d90ce1b86b921b89cff1ed313889803cf13ddd9b744c79c06959a481becc0373
font_02_sfnt_off0001224f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1224F 10684 bytes
SHA-256: 7910b876d5c857ad815a5aa97345817ac41b7ea23ee7c90ebb7505040392c83e