Malicious PDF — malware analysis report

Static analysis result for SHA-256 fbc831b203dafb6a…

MALICIOUS

PDF

95.4 KB Created: 2021-08-08 06:26:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ec48d751e93602912a2b7e350343973f SHA-1: 111b9df7f0efbaba11b1e85415739de4f66f89d3 SHA-256: fbc831b203dafb6a8872375d38829beacdac41c0dbcfd8f31b9773e2728cac41
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links pointing to external websites, many of which are hosted on compromised CMS platforms. The ML classifier strongly indicates maliciousness, and the heuristic firings suggest this PDF is designed as a link farm. No scripts were extracted, but the primary attack pattern involves directing users to potentially malicious or SEO-abused content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9962

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=how+to+write+a+grantor+letter PDF link annotation
    • https://nakipoglugroup.com/upload/ckfinder/files/texosunuwod.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/43be3247bd3bb845f72edf920bee9a9f/xejowinakez.pdfIn PDF document text
    • https://zerling.eu/nico/images/files/lafogizebe.pdfIn PDF document text
    • https://bloc-immo.com/images/57123186198.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/42irhfgipcccj2hg0f1qqsq3f7/nitigef.pdfIn PDF document text
    • https://uppersanduskyrotary.com/cms/files/File/zofax.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/poxate.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/11611583108.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/83923834061.pdfIn PDF document text
    • http://studiotecnicoforace.eu/userfiles/files/zidapul.pdfIn PDF document text
    • https://securityguardsupply.com/php/uploads/file/68067864928.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/a30f42f2007e517898978827d5efa519/nosavixotodat.pdfIn PDF document text
    • http://bethanybaptistcolumbus.org/clients/75549/File/nuwuge.pdfIn PDF document text
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/iapf7c1hhcqf1j2bubh4bavq04/21370256246.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/4d848fd737cbfcf6a83f648e0699eff3/22107214789.pdfIn PDF document text
    • https://karatenarrewarren.com.au/ckfinder/userfiles/files/11112153917.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/58ce8d562e0be9dc3070b5434f3b5d57/zegitefibuk.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/50766235454.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160a14e4dec6ca---39232410135.pdfIn PDF document text
    • https://www.techsrollout.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dd5ac4e92e---42924988869.pdfIn PDF document text
    • http://gomientrung.vn/uploads/image/files/39817994023.pdfIn PDF document text
    • http://gernano.eu/gfx/userfiles/files/kanewesopu.pdfIn PDF document text
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/ae4cn57ong46ur5itduab464ba/duzixe.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_off00011377.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11377 10192 bytes
SHA-256: ed058cca52a8d556987b288dd0bcee6db348ce367e7c6e8061d79056dd6e2518
font_01_sfnt_off00012a6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A6C 17380 bytes
SHA-256: a7e1f52d1160236871839cdd4e36407c5d3d7e027029ac86c061143d02a44992
font_02_sfnt_off00015803.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15803 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1