Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae85d8aec6082a88…

MALICIOUS

PDF

81.1 KB Created: 2021-09-03 05:45:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1c30085f5db94dd4c0f2f8e73f143e8b SHA-1: f527e83930165285224ce422d32a53d8b357d8ae SHA-256: ae85d8aec6082a881925c14620919b6bc74b8b61d81d39780490a0eea2629020
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites or disposable hosting, suggesting an attempt to obscure the final destination or evade detection. The ML classifier strongly indicates maliciousness, supporting the conclusion that this PDF is designed to lead users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://smidgel.ru/uplcv?utm_term=strategic+leadership+meaning+pdf PDF link annotation
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087732382092---66144044301.pdfIn PDF document text
    • http://sun-green.be/ckfinder/userfiles/files/wewofe.pdfIn PDF document text
    • http://gshosnab.ru/userfiles/file/44410278291.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607dd43db3d33---80201600320.pdfIn PDF document text
    • https://okazionche.com/files/55283148072.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/385a847177c08fd3538f0f15bc101505/58305533867.pdfIn PDF document text
    • http://ylpqzl.com/ckfinder/userfiles/files/77920539424.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/020d09bff8a043153a22d99e02bbde95/2998622136.pdfIn PDF document text
    • http://www.sphotobooth.com/wp-content/plugins/formcraft/file-upload/server/content/files/160768ca898754---72931168406.pdfIn PDF document text
    • http://mrybalko.ru/files/gafadanoxujedemopavoru.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ca6a6868a8---xosolimelavubutajovami.pdfIn PDF document text
    • http://industriefotografie.ch/userfiles/files/51795672294.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087d922d4428---81527504793.pdfIn PDF document text
    • http://taitung-house.com/CKEdit/upload/files/60547936450.pdfIn PDF document text
    • http://brilsports.ro/userfiles/file///6034544939.pdfIn PDF document text
    • https://dienlanhhonganh.com/images/pic/file/davegezizuxanoxomekotujo.pdfIn PDF document text
    • http://kistours.hu/userfiles/file/37281602952.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/1609b8b2ce6b0f---67423574252.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/6lv6no693lvurprn9iug2tjrpo/11397279885.pdfIn PDF document text
    • https://atphp.ch/userfiles/file/bifatisuseva.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1608765c0dbc07---45715387.pdfIn PDF document text
    • http://tomei4x4.jp/js/upload/files/mukifuxesuduso.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/16077d6bf56d4e---vakimoxufimuxegox.pdfIn PDF document text
    • http://thestarbusan.net/FileData/ckfinder/files/20210814_E7EC153A947A3641.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076f8bcaf850---90830575402.pdfIn PDF document text
    • http://dfwarbitrator.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/8544823136.pdfIn PDF document text
    • 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_off0000db74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB74 16284 bytes
SHA-256: ed2715bc0383fed80f1f9b7c9d400286b7e356df5cf61399c5b76e5f247a04f7
font_01_sfnt_off00010566.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10566 11024 bytes
SHA-256: ebca791f4bee95fa07cc4a474cae8249083cfe75576fa5f5adae8251a6f9c5df
font_02_sfnt_off00011e94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E94 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1