Malicious PDF — malware analysis report

Static analysis result for SHA-256 8334c0f0f7dda816…

MALICIOUS

PDF

77.6 KB Created: 2021-09-05 15:32:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 9c996d54f8d91711fbbd466eb8857ff2 SHA-1: 40f109ff2708d692f05511732a26878fbc9fa7d0 SHA-256: 8334c0f0f7dda81699050a1573faaf67e791d6b2f2caf8e95bb20a4fd0d1641b
96 Risk Score

Malware Insights

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

The ML classifier strongly indicates maliciousness, supported by heuristics identifying the PDF as a link farm pointing to compromised CMS uploads and disposable hosting. The document body is unreadable binary data, but the embedded URLs and heuristic findings reveal a pattern of redirecting users to potentially malicious content. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079d4df80368---6333821063.pdf In PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/344a5ad4ee4f656c199203e8388dacaf/jiludekisarolibalo.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1608e9bb239c2f---magixedajat.pdfIn PDF document text
    • http://www.cenlafilm.com/siteuploads/editorimg/file/32973190050.pdfIn PDF document text
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/df7b919f2a20f385e749b2388df9b0a9/68168453259.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/piemkqavhvnpvd2ojpqt1j4t8a/90298652093.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb7895d13ef---ragabevavanuzajobal.pdfIn PDF document text
    • http://etcad.net/np/upfile/file/gobinenijemuta.pdfIn PDF document text
    • http://studiolaviano.it/userfiles/files/vezap.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16133dcfda52fe---xozomaderejiwuk.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/hsqnarsso1ekeb9vvsn1dknlge/13290147823.pdfIn PDF document text
    • http://akademia-jedenastka.pl/zdjecia/fck/file/75376547040.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/80642693378.pdfIn PDF document text
    • https://nepalaviationmuseum.com/userfiles/files/63508762597.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/wugas.pdfIn PDF document text
    • http://blissrenewbeauty.com/newerac2c/userfiles/file/relekuti.pdfIn PDF document text
    • http://peaceinsrilanka.lk/ckfinder/userfiles/files/98246095885.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d32eea0a754---jowebavukotaluruvavebusu.pdfIn PDF document text
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074fd5a20e9d---22302094104.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/6c23bf948a7b0a56942c91452d23574b/58859345041.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=ogledalce+znanja+matematika+2+pdfPDF 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_off0000c236.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC236 21120 bytes
SHA-256: 5c99cb1990c8ac8dce8bad4301b9929d261741776c0c2268d01a5f49c67600fc
font_01_sfnt_off0000f7dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7DD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ff4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FF4 11000 bytes
SHA-256: c8e7e45304bffaa00258e0cb624f4c5f1508f72781e0d47be66569d688d21db5