Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4fcb28607e73493…

MALICIOUS

PDF

94.8 KB Created: 2021-09-05 12:56:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 91881f7cccda62a92eb8720986c29925 SHA-1: fe9983dd842fc5ba4bd8d0f6d8bbb63e06e7dc1e SHA-256: a4fcb28607e73493716a721456a443acff9fd2cbaba55804f8a85bd1bc83b949
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The document contains a link farm pointing to various PDF files hosted on compromised WordPress sites, suggesting a phishing or malware distribution campaign. The presence of embedded URLs and the nature of the heuristics indicate an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9897

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fc13dae266---67174716136.pdf In PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/36lndci76j68fdor88ak2rvef6/84727384386.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/1a6c5c84b830211c108c058565222ff8/56901579094.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fb15e2a969---duwanedosuzifopikile.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/9544f96c4041fb330c7d278d1720095d/6531045797.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dec50489c17---31548848982.pdfIn PDF document text
    • https://www.chesapeake-lighting.com/wp-content/plugins/super-forms/uploads/php/files/3236538f4a5d471cff519fc3b71960ff/dudetudezuv.pdfIn PDF document text
    • http://ieeepes-thailand.org/app/webroot/files/files/pukorubewiwufurox.pdfIn PDF document text
    • http://ff-engineering.com/userfiles/files/junesawagutoze.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/16083a3e705eea---28915527992.pdfIn PDF document text
    • https://thegioibaobicarton.com/Images_upload/files/vifewowudedutazope.pdfIn PDF document text
    • https://hotelpancharatna.com/assets/userfiles/files/jinenid.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/25317ba585ee184bf5209a1ce7c6d3b7/vetusezizexala.pdfIn PDF document text
    • http://kardelendalgicpompa.com/uploadfiles/file/serafituvanibawizapimel.pdfIn PDF document text
    • https://www.ideaklinikizmir.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c73b58284f---65055037229.pdfIn PDF document text
    • https://nhaccugiare24h.com/uploads/userfiles/file/lagapipuribijubaruteredu.pdfIn PDF document text
    • http://mwcapital.net/ckfinder/userfiles/files/zekalutifukigurelima.pdfIn PDF document text
    • https://charterboatdeliverance.com/uploads/files/189196825.pdfIn PDF document text
    • http://www.klimavill.com//data/editorfile/novanekipusajazobu.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/4b3dc1fa334c542596c999536860f7c6/pumurazinotu.pdfIn PDF document text
    • http://www.anieliasfx.com/uploads/textareas/file/nukojuritakewujadofowuxa.pdfIn PDF document text
    • http://stalmost.pl/userfiles/file/89865802229.pdfIn PDF document text
    • http://acevina.com/webroot/img/files/lamulumipasepa.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b9874badad---34092996206.pdfIn PDF document text
    • http://fixafilm.se/userfiles/file/gagivuruvoduluwo.pdfIn PDF document text
    • http://beastyenergy.com/userfiles/file/89663443109.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=forgotten+realms+campaign+guide+4e+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_off00010a59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A59 11120 bytes
SHA-256: 6c01d4956157cfaa7cfb66bcf83971156a787712b37c39fbb2d88e02dbbaf9af
font_01_sfnt_off0001241c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1241C 18668 bytes
SHA-256: a96ce3de40e0d319e94cd5dfbae84bc3826b856ab99ef0dd6517aa2e5e4ea4c5
font_02_sfnt_off000154c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x154C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1