Malicious PDF — malware analysis report

Static analysis result for SHA-256 61d85be34678a1cd…

MALICIOUS

PDF

72.4 KB Created: 2021-09-06 13:31:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: e9002254dd401b217ac9d72726159d41 SHA-1: 51b757235ce43f304edfb71ac0542915946680cf SHA-256: 61d85be34678a1cd4a2c4699ee1367fd66462d47d099e8d26c0f5517c27539ea
96 Risk Score

Malware Insights

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

The sample is a PDF document identified as malicious by an ML classifier. It contains a large number of embedded URLs, many of which point to domains associated with compromised CMS uploads or disposable hosting, indicating a link farm. The primary purpose appears to be directing users to external resources, potentially for SEO manipulation or to serve further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://kingwaterpure.com/ckfinder/userfiles/files/wuwovama.pdf In PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609049fe212f0---11134250294.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/gugamofexutires.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/2656a591cf33377645d980b318cdf6c3/vaxaganalefojijonenetera.pdfIn PDF document text
    • http://navigator-33.ru/media/file/girexikutit.pdfIn PDF document text
    • http://serdceprirody.ru/userfiles/file/57305679938.pdfIn PDF document text
    • http://aromaonly1.com/yamituki-n/uploads/files/xubab.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/27a9a43365628cf8aed9e88d1dd25e15/zizelaguxirujujurasajofov.pdfIn PDF document text
    • http://hz-kontejnery.cz/ckfinder/userfiles/files/gatixamebusir.pdfIn PDF document text
    • http://cdhsalumni.com/clients/28864/File/junajevijamuzosezefatoton.pdfIn PDF document text
    • https://deniz-sogutma.org/img/userfiles/file/bajuvap.pdfIn PDF document text
    • http://integrotech.com/zdjecia/file/boganixupekiwosa.pdfIn PDF document text
    • http://ingegneriarossi.it/userfiles/files/samifilozamenosegone.pdfIn PDF document text
    • https://www.duffylighting.com/wp-content/plugins/super-forms/uploads/php/files/3b1ec9f11d7623c44ef9145c584a14d9/96077305679.pdfIn PDF document text
    • https://nusantarabet4d1.com/contents/files/kilukez.pdfIn PDF document text
    • http://sistarelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/35554439531.pdfIn PDF document text
    • http://geobigoni.it/userfiles/files/bavivurakokid.pdfIn PDF document text
    • https://ive-cal.it/file/najuluredaremawisuwanumu.pdfIn PDF document text
    • http://lroundup.com/clients/d/d7/d7466da0ad72d96b64793f89c518a0d9/File/23525423648.pdfIn PDF document text
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607dda816526c---49991596776.pdfIn PDF document text
    • http://print-resource.co.uk/ckfinder/userfiles/files/tojezulefete.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=sonoscape+p50+brochure+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_off0000b9f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9F6 11052 bytes
SHA-256: 2f362e2f1a5a943652918a0c2c29092dd3cbc32da7f087d69fe44c35d6171d05
font_01_sfnt_off0000d36a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD36A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eb7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB7C 15912 bytes
SHA-256: b9e7f16c956d90b5c661231069d882fbdd8be5b8a0c87a1b8643cd7c3012a9a0