Malicious PDF — malware analysis report

Static analysis result for SHA-256 fdf42ea431926817…

MALICIOUS

PDF

87.7 KB Created: 2021-06-27 23:47:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: c4dc8da6f433b202f1821091753a24fd SHA-1: 1ccb306c74a0c2d90d50ca74f22286c9f4f4cee2 SHA-256: fdf42ea431926817456b660640c543b10f8b75ac3c510b0f4e366e47a3bcfe1d
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The ML classifier strongly indicated maliciousness, and multiple heuristics identified the PDF as a link farm pointing to compromised WordPress sites. The document body was heavily obfuscated, but the presence of numerous external URIs, many hosted on potentially disposable domains or compromised CMS platforms, suggests a phishing or malware distribution attempt. No scripts were extracted, but the overall structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f68b53f554---11087934091.pdf In PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/98851945078.pdfIn PDF document text
    • https://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/1c85c6bce02792244d9821e733b19900/19197873717.pdfIn PDF document text
    • http://kurier48.pl/files/userfiles/file/7322858057.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed2edf2ac7---91200050596.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/4ml1af8pkqm0qgd86lcl4tk045/60560063523.pdfIn PDF document text
    • http://akgikorea.com/file_upload/fck_upfile/file/sesolafixopajotumu.pdfIn PDF document text
    • http://www.medicellbank.com/userfiles/files/9217979823.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/c31954b655f58e146f6941f260a313f9/pukikirojisavosudozufame.pdfIn PDF document text
    • http://thegioituigiay.net/uploads/files/zawubupusetinekowoxoxo.pdfIn PDF document text
    • http://meandnetworking.com/ckfinder/userfiles/files/venogavanemikux.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/160770faa9161c---90853008825.pdfIn PDF document text
    • http://weingut-suppan.at/files/69457152940.pdfIn PDF document text
    • http://beveragesgs.com/userfiles/file/24462289384.pdfIn PDF document text
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/jhe0717em60mhq5ipo7jmhs531/38811891637.pdfIn PDF document text
    • http://renovator.cz/files/file/83482175687.pdfIn PDF document text
    • https://memoservicesrl.it/file/gajafolokafegumugowozijel.pdfIn PDF document text
    • https://plentis.eu/ckfinder/userfiles/files/91576981334.pdfIn PDF document text
    • https://pousadamarazul.tur.br/wp-content/plugins/formcraft/file-upload/server/content/files/160884262e5372---rimamutidifobumurodig.pdfIn PDF document text
    • https://travelinnsuites.com/nbloom/fckuploads/file/85601552474.pdfIn PDF document text
    • http://extracam.es/app/webroot/arxius/file/menomu.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/lisezaxelu.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/8e6469785b500b12417cc57a6e667d90/kufefavobilunisosunenasop.pdfIn PDF document text
    • http://tryinvest.eu/userfiles/files/51627894998.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b653fc7fd50---2786126739.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=grace+the+only+way+is+essexPDF 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_off0000f2cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2CB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010ae2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AE2 10668 bytes
SHA-256: 39ed05003dc2bb4a0aff77db563978e7f39f9241f30f1a49c3164bfbfb5a4e23
font_02_sfnt_off00012362.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12362 17208 bytes
SHA-256: 7dfceb27e0c787484c15f4cfab65271540514bb1061dbba1f7932c10be5bc442