Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f23190a41fb9044…

MALICIOUS

PDF

81.5 KB Created: 2021-09-04 07:56:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 2787f644165a24a29723ec5df42bd0ba SHA-1: 0a389b8da40d2adb210643521c54fd7aa890a2a3 SHA-256: 8f23190a41fb90441108485391e859af54c54d98560c97a1c0d632fa12ef42f2
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous embedded URLs, many of which point to compromised WordPress sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the PDF is a link farm on disposable hosting, suggesting its primary purpose is to redirect users to these compromised sites. While no scripts were extracted, the structure and URL patterns are indicative of a malicious link distribution scheme, potentially for SEO poisoning or hosting further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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://nomylo.ru/uplcv?utm_term=terapia+cognitivo+conductual+para+ni%C3%B1os+y+adolescentes+pdf PDF link annotation
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/5mbfctg1b4rgeavke4mqdsrkl6/vugixedebevofukifo.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/160885b7c1b9db---xakosuvoko.pdfIn PDF document text
    • http://hjtech.org/admin/upfile/file/92410254021.pdfIn PDF document text
    • http://autobedrijvenindex.nl/images/uploads/noripovogelujojosar.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/88375821123.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/16111b4105b1f8---lorugumaxevazowowuf.pdfIn PDF document text
    • http://www.chiringuitomediterraneo.com/ckfinder/userfiles/files/pefufuwilexajarivewel.pdfIn PDF document text
    • http://ehs1958.org/clients/73155/File/metorexarosux.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/hh03mp2pobsh7436olng2b1mej/15774055217.pdfIn PDF document text
    • https://lion-trading.co.uk/wp-content/plugins/super-forms/uploads/php/files/evke3isoudhgbt051evs935bvk/23085591051.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d096f096e2---55661018843.pdfIn PDF document text
    • http://alnoorcity.com/userfiles/file/gixanasoxet.pdfIn PDF document text
    • https://simon-daulte.com/ckfinder/userfiles/files/46437566346.pdfIn PDF document text
    • http://zzzwchem.com/upload/files/55775936090.pdfIn PDF document text
    • http://theemasternetworker.com/ckfinder/userfiles/files/43299896837.pdfIn PDF document text
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/fe586abc08c7e28ad4940c351d1710dd/77817490478.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/2c04a2f72577e7a35801d753abbf23e7/652401309.pdfIn PDF document text
    • http://doktor-okonski.pl/uploadimg/file/japuneseroponipiwa.pdfIn PDF document text
    • https://flyags.com/editorResources/file///70810488743.pdfIn PDF document text
    • http://fuzoku-kyujin.jp/ckfinder/userfiles/files/besavakawusemakizilofeg.pdfIn PDF document text
    • https://www.rekalibracija.com/wp-content/plugins/super-forms/uploads/php/files/78c81bda9f420790e04569cc45144012/funavat.pdfIn PDF document text
    • http://topp.pl/_topp/file/fomezosetar.pdfIn PDF document text
    • https://doluhosting.com/calisma2/files/uploads/nadejeku.pdfIn PDF document text
    • http://agnieszkapawlik.com/userfiles/file/judodonowukuzowovovinasi.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_off0000d4ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4CA 18256 bytes
SHA-256: 9c0dc4a1f909b0547c10a5b534f7f7874086cee4deb101c6ec3da62839c71c36
font_01_sfnt_off00010321.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10321 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011b38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B38 11244 bytes
SHA-256: a1cc6a73d74fd3e75dac7ce3b5c8c1bc6bf99c9da18a590e411249cbb2329f16