Malicious PDF — malware analysis report

Static analysis result for SHA-256 881cd9fa5759bd17…

MALICIOUS

PDF

70.2 KB Created: 2021-09-28 12:27:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 7f1850cf9f6ab2433d60378fbf6fd407 SHA-1: 94ff2e8e13cecee7b25f9c9c784d751cabcd8950 SHA-256: 881cd9fa5759bd1734cae1828d93ac5d579947ed2d44076daaa8c970c342f8d2
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to PDF files hosted on various domains. Heuristics indicate this is a link farm, with some links pointing to compromised WordPress upload storage. The ML classifier strongly flagged this PDF as malicious. The primary purpose appears to be directing users to external resources, likely for phishing or to download further malicious content.

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://viboot.traigiongthuha.com/ckfinder/userfiles/files/faper.pdf In PDF document text
    • https://rabudiagnostic.com/userfiles/files/zujurerefofovoragomasilex.pdfIn PDF document text
    • https://aldurra.ly/images-editeur/img/file/47044953457.pdfIn PDF document text
    • http://scherzerpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/2963633629.pdfIn PDF document text
    • http://drdj.friend-match.com/upload/files/vodowis.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613eb5e93de61---13672324581.pdfIn PDF document text
    • https://honghow.com/ckfinder/userfiles/files/nozikewojekumafabubotiz.pdfIn PDF document text
    • http://zjhywt.com/images/upload/File/vajedexazemume.pdfIn PDF document text
    • http://3dprofi.net/images/uploads/file/96091815606.pdfIn PDF document text
    • http://pusheng168.com/uploadfiles/20210916214619.pdfIn PDF document text
    • https://12shio3.com/contents/files/wobuvenefewososubax.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/16138d01907c30---zogotowavi.pdfIn PDF document text
    • http://druckmaschinenservice.com/uploads/fce/files/45812729402.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ac9b2b1580---daladuwivevetepofi.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/3cecbc82adfa30e11744a83232da0990/gosizerulopux.pdfIn PDF document text
    • http://vicc.huh.hu/UserFiles/File/xogomuworom.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/161357cc5bc0e5---golij.pdfIn PDF document text
    • http://fuku-zou.com/userfiles/file/2156188788.pdfIn PDF document text
    • http://planet-for-events.de/userfiles/file/vuwiporov.pdfIn PDF document text
    • http://yongchengtech.com/uploads/files/202109161212118715.pdfIn PDF document text
    • http://mn-print.ru/ckfinder/userfiles/files/47412329579.pdfIn PDF document text
    • https://legyenegyjonapod.hu/userfiles/files/56822027519.pdfIn PDF document text
    • http://tantusmarina.com/UserFiles/file/paruvet.pdfIn PDF document text
    • http://feuerwehrobrigheim.de/upload/files/99629984712.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=hacksaw+ridge+torrent+free+downloadPDF 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_off0000b2b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2B8 14872 bytes
SHA-256: c4e5ef6effc1c6b1ce7b374b7188162850d218efb74b602f928d2bab98be7d70
font_01_sfnt_off0000d862.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD862 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f079.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF079 10820 bytes
SHA-256: 43ec5e13c50df7be301adf2819dbe887bee269a2d27a31772272b5fcb0fbdde8