Malicious PDF — malware analysis report

Static analysis result for SHA-256 582ed7b519d7baff…

MALICIOUS

PDF

88.9 KB Created: 2021-09-05 21:27:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: cba031546f342c34b0a9cb2e5c0b5188 SHA-1: d6ff11da193f9e95253d49f55cd1a2fff3ac9b37 SHA-256: 582ed7b519d7baff50ab3c2c63a199f410fdba175471500b7e56c18ba7beefa1
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm or phishing lure. The ML classifier strongly indicates maliciousness. While no scripts were explicitly extracted, the presence of embedded URLs and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' point towards an attempt to redirect users to potentially malicious content or phishing sites.

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 https://crysiq.ru/uplcv?utm_term=catalogo+de+bujias+ngk+2017+pdf PDF link annotation
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607589dc79f85---17035874933.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/16094b3416d9d8---53706930071.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608065e64db0e---66314100170.pdfIn PDF document text
    • http://ciaooo.ru/uploades/userfiles/file/53735590314.pdfIn PDF document text
    • http://bruisedreedfoundation.org/clients/4/4d/4d9d7eec3bf3a09fa0457ace138f6a4e/File/lawesififijuvegaririm.pdfIn PDF document text
    • http://nordicaluminium.ru/userfiles/file/77587829662.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081db10930fe---19639886968.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/ruvuge.pdfIn PDF document text
    • http://qlionshousing.ca/userfiles/file/nejam.pdfIn PDF document text
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/16092c2c04e07c---42635011361.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16123ad1949f74---tinedewokitetumakiguk.pdfIn PDF document text
    • http://jurabos.nl/include/editor/file/fudidubefulupevogu.pdfIn PDF document text
    • https://drivetripper.com/userfiles2020/files/xiwavoje.pdfIn PDF document text
    • https://juhaszautovill.hu/userfiles/file/rizaxokulusawumumisipeku.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1610d35a917a2f---61085414757.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160748fd31009e---94919242546.pdfIn PDF document text
    • http://contelex.it/userfiles/files/74063407030.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/929e5852c098821daee706a43e24091d/gofat.pdfIn PDF document text
    • http://nessium.net/userfiles/file/nogikepuviloxaz.pdfIn PDF document text
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/160847fb51927a---64423101534.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/86932573385.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b14ead4e23d---pufezovom.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/frusaaiubb47rbffdsqnplldmc/vililukejarajon.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083a69b7ebc2---4413289314.pdfIn PDF document text
    • https://systematix.pl/userfiles/file/wopapi.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_off0000f236.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF236 11408 bytes
SHA-256: 18c38da7ff6785c07d3ccef375044af099fa3d7ea00a44bd15027ca3898ce385
font_01_sfnt_off00010cf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CF6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012508.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12508 19148 bytes
SHA-256: b308957cb247db6775fe3618b6cb06836de17a1f746921a6daf955ff4e77b468