Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8dc08acc24a1d71…

MALICIOUS

PDF

74.6 KB Created: 2021-09-21 16:17:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f0280377c97624505470f6272c80aa8f SHA-1: fe6a368b82aa51bb656a5fd967ace1fef71ded38 SHA-256: b8dc08acc24a1d71cc5b1acfb7e4cf0e6073c2a0543b988a472275ec8c355db8
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised websites. The presence of embedded URLs and the nature of the heuristics suggest an attempt to exploit users by directing them to malicious content, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://h16hr15k-h19hr37urn.com/contents/files/vubonederowevabijebiri.pdf In PDF document text
    • http://wxeina.com/userfiles/files/8156971510.pdfIn PDF document text
    • http://delfosventures.net/userfiles/files/towatobiperinegaradu.pdfIn PDF document text
    • https://fontaine-eva.fr/userfiles/files/fetifepimemefuwikofaniz.pdfIn PDF document text
    • https://abandassociates.com/ckfinder/userfiles/files/80284291821.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/o2h1ls1fv49dodcc13dlcsfj2f/rutadazeg.pdfIn PDF document text
    • http://talentfuturesservices.com/sharpinstitute/images/files/62321135601.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/a050fc9ae51a2da7d9e0521b8f9aa81b/38924201800.pdfIn PDF document text
    • http://www.its-dph.cz/admin/fckeditor/editor/userfiles/file/33639176131.pdfIn PDF document text
    • http://alsace.annuaire-regional.com/ckfinder/userfiles/files/tugim.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/16141a6b539569---bizusogiwaxawuderuratowu.pdfIn PDF document text
    • http://turksebruiloften.nl/userfiles/file/naxikapusumexesazum.pdfIn PDF document text
    • http://tao-oita.com/admin/upload_filesfile/poranaremop.pdfIn PDF document text
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16133210779202---31124556100.pdfIn PDF document text
    • http://vekosgroup.ru/userfiles/file/vubojuba.pdfIn PDF document text
    • http://zekidilektekstil.com/images_upload/files/rixaw.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/c729403c3102a73f29b185951d9246d3/57437365457.pdfIn PDF document text
    • http://esenkardeslerinsaat.com/resimlerfiles/dalumuzinizomemaje.pdfIn PDF document text
    • http://plechotice.sk/tmp/file/36755296233.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/2d57d73dd909ed945837bdd94695a168/bumexarijezo.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613a79ff108c7---62370749825.pdfIn PDF document text
    • https://theurbanthinktank.com/files/gadesizupozagowasekilofad.pdfIn PDF document text
    • http://vaynhe.com/upload/files/54103009442.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=view+private+instagram+androidPDF 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_off0000bed4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBED4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d6e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6E6 16920 bytes
SHA-256: aa826da6e6b54acd1ff4cc3afd5a34733c5e69a85f216b81fd2160baee75ff51
font_02_sfnt_off000102b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102B5 10808 bytes
SHA-256: b5da055570c27fc204db97a84b0d3f0c04d4d3cd9dd0c3e4c0fe7d8d977b30e7