Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b4bb4c0c6478a05…

MALICIOUS

PDF

81.0 KB Created: 2021-09-06 06:08:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5d2d35e3468943d862b615d9b4738d61 SHA-1: bcae66b89c6cd0eafbfdee82f6a25f4bb9a7bf49 SHA-256: 5b4bb4c0c6478a05eb1ab518433521199aa592dc137093f46b2dc2fc7f2861da
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple compromised WordPress sites and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The ML classifier strongly indicated maliciousness. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malware distribution or phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://alrukn.co/userfiles/files/moponef.pdf In PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b663f775529---12648225484.pdfIn PDF document text
    • http://jtg-antracyt.pl/files/file/delowedizuri.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f64b438c59---84588447114.pdfIn PDF document text
    • http://adec-interiors.net/Uploads/file/80770412386.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/d6df48cb785d5c4ed6f6e60eb68442b2/80838529756.pdfIn PDF document text
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/vizenaxoz.pdfIn PDF document text
    • http://nenkin-t.com/upload_img/ck/files/46245984401.pdfIn PDF document text
    • http://lightningriskassessment.com/ci/userfiles/files/19432462798.pdfIn PDF document text
    • http://lnaixi.com/userfiles/file/20210629082914_895944962.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b1723ba9c5d---kazuporenepujat.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021071519251450.pdfIn PDF document text
    • http://hosungtour.com/FileData/ckfinder/files/20210802_783D1DCA9D0F5B08.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3eb30a5412---jukezurutetusaril.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160874695cc1a6---toreluj.pdfIn PDF document text
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/3fabe7cb5ade94810b0044795fc5a61d/pukipuwedobuna.pdfIn PDF document text
    • http://wedding-box100.com/uploads/files/202108241824425658.pdfIn PDF document text
    • http://apsons.eu/files/file/fagas.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160e4c9300575d---daronekuxuzafuleji.pdfIn PDF document text
    • http://elonsummerstorage.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609129ea67553---40554657848.pdfIn PDF document text
    • http://immobilieninvestors.de/userfiles/file/wemopuxamipabo.pdfIn PDF document text
    • https://austdoorcaocap.com/upload/files/tonanuragowawufegisazum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=honda+accord+2013+service+manual+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_off0000d525.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD525 18228 bytes
SHA-256: 785bfe906241d01d35ef975555fc44aac714ea8a19e4af88fc91ab26031b46db
font_01_sfnt_off00010416.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10416 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C2D 11308 bytes
SHA-256: 72fa97f182b200c30a3267a1b796dfa57a9993b86f7849d173db4dfdc4e6b6e6