Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b6003a3f3730558…

MALICIOUS

PDF

71.1 KB Created: 2021-09-09 14:19:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 4033b82b7a4d84f8a3b6dac0b87dc244 SHA-1: f33fa8713712eb495af47f73b8bded2b66b14b49 SHA-256: 3b6003a3f3730558864055741145d3b8134683a04e24b3d2313a522e766b44b2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The file was identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Several URLs point to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF format and embedded URLs suggest potential exploitation of PDF vulnerabilities or JavaScript execution for further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://leonardscopysystems.com/home/leonards/public_html/ckfinder/userfiles/files/dunagun.pdf In PDF document text
    • https://keralatemples.info/ckfinder/userfiles/files/xazusotuvedad.pdfIn PDF document text
    • https://webkapper.nl/ckfinder/userfiles/files/86359385804.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/file/71057446928.pdfIn PDF document text
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/j61s76pbo0bpinemilagqlvnv7/6117866818.pdfIn PDF document text
    • https://aquatrustfina.com/userfiles/file/xigerojobowajozikexu.pdfIn PDF document text
    • https://e-uchebnici.com/img/file/2090226667.pdfIn PDF document text
    • http://carrasvilla.es/uploads/files/wifenobumajufi.pdfIn PDF document text
    • https://firesystem.ro/imagini_ws/jaluvegevupomogopewaz.pdfIn PDF document text
    • https://gencerenerji.com/resimler/files/fiwikuxezaxunojunewimefu.pdfIn PDF document text
    • http://pieseclimaauto.com/files/file/levokoz.pdfIn PDF document text
    • http://mijinmotor.com/fckeditor/userfiles/file/wagaburiluber.pdfIn PDF document text
    • https://e-midas.ro/files/file/55582242513.pdfIn PDF document text
    • http://indcms.testingmachines.com/images/file/86781009081.pdfIn PDF document text
    • http://paneldeconsos.com/userfiles/file/24237869166.pdfIn PDF document text
    • http://huzatfokozo.hu/editor_up/31329527111.pdfIn PDF document text
    • https://cv-vezouze.fr/media/file/lezedorugodoruxoxemevux.pdfIn PDF document text
    • http://tnetimes.kr/upload/file///sawirukaboj.pdfIn PDF document text
    • http://terralis.eu/catalogue_dynamique/file/23833292422.pdfIn PDF document text
    • http://alda.pl/ckfinder/userfiles/files/56912894093.pdfIn PDF document text
    • http://uniontsg96.ru/admin/ckfinder/userfiles/files/wadoruwimekajuvagax.pdfIn PDF document text
    • https://shen-su.eu/gfx/userfiles/files/17257046322.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613601ff42088---xuvafezonejatij.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/othohblvf363l4rpo273jlt9v6/93048732338.pdfIn PDF document text
    • http://teenmag.cz/userfiles/file/77312546708.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=mobdro+firestick+downloadPDF 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_off0000b5d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5D4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cdeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDEB 10780 bytes
SHA-256: bcc1217518837c9831cae2c4e348bb7f24eff70d28aeed3301253743b04a3ec0
font_02_sfnt_off0000e6f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6F3 15648 bytes
SHA-256: 29325c8d82b4947fb9cd889be7d893f93f73c07763a28bc6bf0ff4c89dade75d