Malicious PDF — malware analysis report

Static analysis result for SHA-256 56f8f93ea48779b0…

MALICIOUS

PDF

70.6 KB Created: 2021-09-02 17:49:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 66178a2d5aab162ed8dfd41a93f98c79 SHA-1: 6c612157944195ed3bcc80e2776d24faa3e2ce67 SHA-256: 56f8f93ea48779b0c1a0ba785cf86db33593c94328f8897b61bb99aa6d1da68c
96 Risk Score

Malware Insights

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

The PDF file contains a large number of external URIs and is identified as a link farm, suggesting its primary purpose is to redirect users to other sites. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple compromised CMS upload links further supports a malicious intent. No scripts were extracted, but the structure and URL patterns indicate a potential for hosting or distributing malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://krisoc.ru/uplcv?utm_term=sketchup+2017+tutorial+pdf+download+free PDF link annotation
    • http://canvangdientu.com/images/file/gufirunumimuwumebumuxix.pdfIn PDF document text
    • https://bibliotheque-des-arts.ch/ckfinder/userfiles/files/12369357468.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/a15cc6e3827bf30e5394ae3ae524cfaa/67472990738.pdfIn PDF document text
    • https://postelezmasivu-zlin.cz/ckfinder/userfiles/files/37080893576.pdfIn PDF document text
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080c9154efa8---fupovoxikupiguted.pdfIn PDF document text
    • http://nsdadventist.org/FCKData/file/98848342157.pdfIn PDF document text
    • https://juvelyrikoscentras.lt/Files/file/76731680093.pdfIn PDF document text
    • http://thuexe7cho.vn/upload/files/46873593251.pdfIn PDF document text
    • https://shidoremicrosys.com/media/18498203712.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/d8f82u7mt3fjn27d3ui619dqic/tegonas.pdfIn PDF document text
    • http://www.catedralirodahaz.hu/data/editorfile/36220545182.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608a28ba7a138---4276130526.pdfIn PDF document text
    • http://schokoladenfontaene.de/idata/gebezekororajoxazafime.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c133f18f3c2---47532977660.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/a870362ebe0c16db66dac6136304af35/basurubumaxupaxeg.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4ebbd4b586---madejonujemarijutogom.pdfIn PDF document text
    • http://webursitet.org/Files/file/ragafizunaluzawa.pdfIn PDF document text
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/742769fb114e5d3602c2a6d434c09958/xugixujomoruw.pdfIn PDF document text
    • http://lokalsport.no/userfiles/file/12206574130.pdfIn PDF document text
    • https://tgvl.in/uploads/fck/files/99142565464.pdfIn PDF document text
    • http://klaaswester.nl/img/file/13554718145.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/50d5babdf8e75bcd617c2c0d74935eba/60840059423.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_off0000b36b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB36B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cb82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB82 11244 bytes
SHA-256: 4a40d31decc3bd4c05dcd993ee745d76552d44d49824bcd5a5799b1309b0308e
font_02_sfnt_off0000e602.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE602 15368 bytes
SHA-256: 871522581689f5999a0d9c522aa4c47af83cc81436e5d3f1dea83d81dfd042a8