Malicious PDF — malware analysis report

Static analysis result for SHA-256 6e81e5df46c1ddf5…

MALICIOUS

PDF

88.9 KB Created: 2021-07-31 21:52:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c1083e16952df474ac2d08f939207884 SHA-1: 69c3cda63dad8feb919626bed9b62582b75ea2fa SHA-256: 6e81e5df46c1ddf58473de07d74c1f8767f41540c0ae49f4ace21a9f850b0565
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the structure and URL patterns suggest it's designed to lead users to potentially harmful content or facilitate SEO manipulation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://nada70.org/userfiles/file/11827655865.pdf
    • http://aerotechgroup.ru/img/outer/files/gowoga.pdf
    • http://bigband-ulm.de/userfiles/files/41782893904.pdf
    • http://eprdel.cz/userfiles/file/77965090041.pdf
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/8943d3ef9768d9a820711e36ffbe3ec3/44208159656.pdf
    • http://jikaramen.com/uploads/files/69033635839.pdf
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/9b29354f6c301a7c7ce1c4649b25ded8/44640250607.pdf
    • http://sjhrz.com/images/upload/File/nodatu.pdf
    • http://remaining-mc.de/userfiles/file/6155190437.pdf
    • http://akcjonariusz.com/UserFiles/file/27787886075.pdf
    • http://capri.lt/userfiles/files/24065811232.pdf
    • http://irina-beha.com/ckfinder/userfiles/files/20002749526.pdf
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c76b274deeb---zasugosusanuvarepa.pdf
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/160a6f76bd69e2---43214068293.pdf
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/3894240c7856130fb5a94a0c834bb651/kafixaxuwara.pdf
    • http://aarogyamedico.com/userfiles/file/jedil.pdf
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/1cde588c9131a6f0d1c1c33be4a8bcf1/20189312738.pdf
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16080447779ce4---kesekuxanu.pdf
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160da5c8586744---30583510368.pdf
    • http://ezstreetautosales.com/clients/876244/File/kibubidatisanakejekote.pdf
    • http://brezov-gaj.si/uporabnik/file/goboxakij.pdf
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/7a2b0149e62ef9cbdf8c3374828b973e/60760238822.pdf
    • http://jaika.in/images/documents/files/43821836760.pdf
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba66d7343e4---16692908261.pdf
    • https://panama4d.com/contents//files/81501494658.pdf
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc207409cdd---72528987391.pdf
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3a4fbbc0f2---83363586269.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+play+hide+and+seek+game
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f60d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF60D 16792 bytes
font_01_sfnt_off00010e1f.bin
327e79c1109e0c0ae82ad9a37482f02f9b4eae638dbcd1290c91eb2fabd13dd4
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E1F 17316 bytes
font_02_sfnt_off00013baa.bin
dc61e9a9f7aad267387fe7f8d30818ebef52d68e38c629973e3c116eb2ed6d28
pdf-font-stream PDF embedded font (sfnt) at offset 0x13BAA 11020 bytes