Malicious PDF — malware analysis report

Static analysis result for SHA-256 2158de4e8b35928d…

MALICIOUS

PDF

72.8 KB Created: 2021-09-17 02:13:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 6eea4710624a431e239c500ff39a0b84 SHA-1: b7d79c9972d3b9ce809e02c98070801420ee7583 SHA-256: 2158de4e8b35928d71bacae68e2b83b180bb244b63e4a67a11f9b2a197750853
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to PDF files hosted on compromised CMS upload directories or disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this document is a link farm designed to redirect users to potentially malicious content. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://acgroupenterprise.com/userfiles/file/rejusigu.pdf In PDF document text
    • https://e-ssuances.com/ckfinder/userfiles/files/gabugemitawifu.pdfIn PDF document text
    • https://pvesc.vn/uploaded/file/madobamumolebegixoba.pdfIn PDF document text
    • http://tabbanbros.com/admin/fckeditor/editor/filemanager/connectors/upload/file/nezamuxodaberejivi.pdfIn PDF document text
    • https://adikkedua.com/contents/files/xubijadogezo.pdfIn PDF document text
    • https://kitapkaplama.com/upload/ckfinder/files/boliwunonumamoguz.pdfIn PDF document text
    • http://enjoy.sk/editor_uploads/system/files/11839395263.pdfIn PDF document text
    • http://vervesimuhub.com/userfiles/file/9640407762.pdfIn PDF document text
    • https://www.funes.gob.ar/ckfinder/userfiles/files/fegome.pdfIn PDF document text
    • https://inarsindbari.org/uploads/pafawetiwezewigikube.pdfIn PDF document text
    • http://bellina.pl/userfiles/file/dinapazif.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613432b77427e---38596601272.pdfIn PDF document text
    • http://vanguardhungary.hu/userfiles/file/wizexunowerugidofet.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bb5e156b4b---48690809841.pdfIn PDF document text
    • http://www.eau-msu.ru/ckfinder/userfiles/files/feripejisaxewopufip.pdfIn PDF document text
    • http://qishuochem.com/siicea/userfiles/file/83825795842.pdfIn PDF document text
    • https://vnycc.com/userfiles/file/74388377435.pdfIn PDF document text
    • http://saatgaamkansarasamaj.com/admin/uploads/files/pusifuwateranate.pdfIn PDF document text
    • https://fleuriste79.fr/ckfinder/userfiles/files/11434449770.pdfIn PDF document text
    • http://linkingpeople.info/userfiles/file/68957592004.pdfIn PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/d804efa1a00c9365ca950df5dceac51d/10311220069.pdfIn PDF document text
    • https://tonerihned.cz/userfiles/file/91903363240.pdfIn PDF document text
    • https://chokysitohang.com/Uploads/userfiles/files/44216742799.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=high+art+full+movie+onlinePDF 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_off0000b8bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8BB 10648 bytes
SHA-256: 87b6dd687c7e08db0ea6bb5f40e84b9a7be673683f8e58f78d1dec098a73b41f
font_01_sfnt_off0000d0e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e8fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8FB 17216 bytes
SHA-256: 2f0fec0c558a1878428703f58b761a8c1e1e3049d7801c47cc9c221672f35a05