Malicious PDF — malware analysis report

Static analysis result for SHA-256 72de188b1bd96227…

MALICIOUS

PDF

84.1 KB Created: 2021-09-06 05:50:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1cfcf51a636278f04e157f1ee80c61fc SHA-1: 900465d0b716f660232a35572e301ee3e7b04554 SHA-256: 72de188b1bd96227a18e440a65bae1d445938c035bd72df8e2950a49c434a967
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to PDF files hosted on various domains. Several heuristics indicate this is a link farm, with some links pointing to compromised CMS uploads. The ML classifier strongly flagged this PDF as malicious, suggesting it's part of a campaign to lure users to malicious content or potentially download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://huntic.ru/uplcv?utm_term=characteristics+of+research+paper+pdf PDF link annotation
    • http://myboydfamily.com/clients/7/7f/7f513a2250c12de81a70a6735749c289/File/nanebiv.pdfIn PDF document text
    • http://firegallery.ru/img/upload/14960457984.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095b5beea90e---demaletewufirafudatopedu.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/nigilukot.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160b0845f69417---folivir.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/gijopulikejijobudafovuluj.pdfIn PDF document text
    • https://sport-jicin.cz/dokumenty/99446205480.pdfIn PDF document text
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/4v3t1kcpb11f43agaooi94mv28/29986939482.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607197d62facc---nelifitajefotana.pdfIn PDF document text
    • http://poornasreehomeoclinic.com/ckfinder/userfiles/files/purimomafavitaxop.pdfIn PDF document text
    • http://wolfpackbasketballacademy.com/content_docs/voliselojujofepow.pdfIn PDF document text
    • http://alkanboya.com/files/file///97844932875.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/fubp6i1kllj2qg13gf25ql2kk7/xamukabepifokofutolonotu.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/042e3b545ce9024e5ac415d51daecae4/22882285417.pdfIn PDF document text
    • http://etnorom.hu/pictures/31446375936.pdfIn PDF document text
    • https://hmanagement.net/userfiles/file/67035450852.pdfIn PDF document text
    • https://europacreativaeuskadi.eu/files/galeria/files/95098945213.pdfIn PDF document text
    • https://ewdel.cz/ckfinder/userfiles/files/widedilaponiveko.pdfIn PDF document text
    • https://sonarmusic.hu/up_image/file/41245290757.pdfIn PDF document text
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/v288c5575b20nbvfq62m3866a7/232280866.pdfIn PDF document text
    • http://paliukenas.lt/i/File/lifutelalasufe.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_off0000e332.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE332 18468 bytes
SHA-256: e91221b0f93eeeeecf23c782b8dfb7d7d306790694568ce47aaf3265d43be0b4
font_01_sfnt_off0001125e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1125E 10596 bytes
SHA-256: 3d94742d342778fdca71988069b606a057e6af8e4a7d10e0c97ea697de15fc58
font_02_sfnt_off00012abf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ABF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1