Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5f451038e257aba…

MALICIOUS

PDF

105.8 KB Created: 2021-10-08 18:33:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 167d27b89904643bc8b78ddb3791b01c SHA-1: 8172ce542f5844e3fcb1345233a78958d154c5b1 SHA-256: f5f451038e257aba293c779daadd6e059742746dc43e611bd1f4a900a0e34c04
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. The primary purpose appears to be directing users to external, potentially malicious, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9867

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://crewmak.ru/uplcv?utm_term=kant+and+the+categorical+imperative PDF link annotation
    • http://gopherandsquirrelcontrol.com/admin/images/file/6330754336.pdfIn PDF document text
    • http://isitekmuhendislik.com/userfiles/file/62688394156.pdfIn PDF document text
    • https://inoxquochoang.com/app/webroot/files/images/pages/files/kegatenazu.pdfIn PDF document text
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/95475337801.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/16133713f9eb55---rojumananoxurufudusew.pdfIn PDF document text
    • http://linker-apps.com/files/tizuxapatoxuvixunigeliju.pdfIn PDF document text
    • http://tpt.taipei/asset/uploads/files/xinofuluxoped.pdfIn PDF document text
    • http://www.insight-assessment.com/ckfinder/userfiles/files/72551925832.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16140e8037d043---sasozusuzutopavadetawo.pdfIn PDF document text
    • http://fra2ange.it/userfiles/files/69083431539.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/16142ed1363c8e---xulafet.pdfIn PDF document text
    • http://winterwonderlandzundert.nl/uploadimages/files/xomavagewemojoniwug.pdfIn PDF document text
    • https://kalashad.com/userfiles/file/32129347398.pdfIn PDF document text
    • https://michelbarbot.com/upload/files/51925142399.pdfIn PDF document text
    • https://recapress.com/ckfinder/userfiles/files/63528468422.pdfIn PDF document text
    • http://digifast.cz/userfiles/79286348440.pdfIn PDF document text
    • http://kojeneckezbozi.eu/userfiles/file/22157701788.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16136d7619f2a0---36737564200.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613312f8c2ef4---31569769888.pdfIn PDF document text
    • http://giadinhlaurenso.org/upload/files/zazit.pdfIn PDF document text
    • http://lsphc.com/userfiles/file///88019852245.pdfIn PDF document text
    • http://urduhadith.org/survey/userfiles/files/fasobiresafewojakapeba.pdfIn PDF document text
    • https://ratoempat.com/contents/files/90920423959.pdfIn PDF document text
    • https://kham.vn/userfiles/file/79032455584.pdfIn PDF document text
    • http://studiotecniconuti.it/userfiles/files/winanitax.pdfIn PDF document text
    • http://sun-green.eu/ckfinder/userfiles/files/83146025399.pdfIn PDF document text
    • http://bosch-elektronarzedzia.pl/catalog/file/67858752954.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_off00013390.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13390 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00014ba2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14BA2 20324 bytes
SHA-256: 871a0a59c0c4b86f9f7504012c64f2f882206b3c900a7ab19b16b5dfe4168412
font_02_sfnt_off00018072.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18072 10852 bytes
SHA-256: 883829e5dcbe214a4c240891a43d6ba55ae828b9db76b2d7883fa0740cbc0f02