Malicious PDF — malware analysis report

Static analysis result for SHA-256 e860cdbd71348e81…

MALICIOUS

PDF

79.8 KB Created: 2021-09-19 07:42:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 07ea2d6271d4066ec1e53a3c2a8368f7 SHA-1: 5f08123a62f0a774e08f1d7d8273e202d31d1553 SHA-256: e860cdbd71348e81fab6ed878762f9fa41862d1160c4c33f47b22be421814443
96 Risk Score

Malware Insights

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

The ML classifier strongly indicates maliciousness, and heuristics identify the PDF as a link farm pointing to compromised CMS uploads and disposable hosting. The document body is unreadable binary data, but the embedded URLs and heuristic findings suggest the primary purpose is to redirect users to malicious sites. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://home18.ru/wp-content/plugins/super-forms/uploads/php/files/6c84ec48cbdb15d0ade7b7cfcdeedbf7/93957844653.pdf In PDF document text
    • https://nsstore.mx/ckeditor/ckfinder/archivossubidos/files/67781051320.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/84253165290.pdfIn PDF document text
    • http://xn--nellieskche-0hb.de/userfiles/file/99141376398.pdfIn PDF document text
    • https://bientannamhuy.com/wp-content/uploads/files/rufijonar.pdfIn PDF document text
    • http://ychnjl.net/userfiles/files/17986341673.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-9-6/20210906015759388920.pdfIn PDF document text
    • http://culbertsonlawyer.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/damov.pdfIn PDF document text
    • http://kimyasaldubeller.com/upload/ckfinder/files/xisifawomupesakuw.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/161407eeb005e5---54257470483.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161394344916b3---lenuzulilazuzizetipo.pdfIn PDF document text
    • http://topp.pl/_topp/file/lowijegusaxonosekoze.pdfIn PDF document text
    • http://ciaomamma.hu/editor_up/86070466333.pdfIn PDF document text
    • http://e-menu.hu/editor_up/xabexowizifav.pdfIn PDF document text
    • http://djpress.pl/Image/files/34694248950.pdfIn PDF document text
    • https://etonbio.com/newsLetters/images/file/99607151209.pdfIn PDF document text
    • https://stephankeppel.com/userfiles/file/welufixotusoxebubupije.pdfIn PDF document text
    • http://kystar.net/filespath/files/20210916102955.pdfIn PDF document text
    • https://renfrewareahealthvillage.ca/ckfinder/userfiles/files/10516355601.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142054cc5d6a---lofubuvatajo.pdfIn PDF document text
    • https://lhorizon.ca/uploadHorizon/file/77854622909.pdfIn PDF document text
    • http://naoshima-tours.com/images/blog/file/46412364477.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=copy+my+phone+dataPDF 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_off0000d594.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD594 10396 bytes
SHA-256: 51895b5d87360c7afdfe2742211eb4e33e7c1d8107ec6240a8ea1e465b4f70e7
font_01_sfnt_off0000eced.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECED 17532 bytes
SHA-256: 24695d91429693fba1decc59680bcd6370fafd5b0e18f4ef8a24934d96ecb4bc
font_02_sfnt_off000119bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1