Malicious PDF — malware analysis report

Static analysis result for SHA-256 4eb21679e3c2828f…

MALICIOUS

PDF

81.2 KB Created: 2021-06-11 03:22:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 55b75f71a44bf003b75af6e22ed3ed16 SHA-1: 7e85d804bc4b7d2c98177cad3cea9d9aa3689689 SHA-256: 4eb21679e3c2828f0637ed3ff5c90006d1c99fb691c642ed783685f0c444c577
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links pointing to compromised WordPress sites and other disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a phishing or downloader attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://krisoc.ru/uplcv?utm_term=ahsoka+2003+clone+wars PDF link annotation
    • http://proxima-design.cz/files/file/3290677268.pdfIn PDF document text
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/7btu28n0u3j98ukarm8jfekuvu/52806256426.pdfIn PDF document text
    • http://hy-concrete.ru/d/files/77778076220.pdfIn PDF document text
    • http://sujitonweb.com/userfiles/files/67870039187.pdfIn PDF document text
    • https://beatmuellerfoto.ch/userfiles/files/86239846670.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/4iad3chvtjkhu5ed82vhh6ribt/96058609481.pdfIn PDF document text
    • https://www.frankreich-ferien.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1606d04f66876c---2697358160.pdfIn PDF document text
    • https://gradeagroup.com/wp-content/plugins/super-forms/uploads/php/files/eg47duqpab2pn9g96gkctgkf2a/xajesi.pdfIn PDF document text
    • http://africanhairbraidingsalon.com/userfiles/file/nisofajofeb.pdfIn PDF document text
    • http://allasclub.com/campannas/file/72870361184.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/b83fc6deecbadcc1d14a8a618c81792a/kewudekidepokipojoveb.pdfIn PDF document text
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/16094c9c7be9cb---47111922525.pdfIn PDF document text
    • http://firegallery.ru/img/upload/gejupewumunipapopetawimom.pdfIn PDF document text
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/e9gb0monihft00u903qghkiia3/vejogijobiru.pdfIn PDF document text
    • https://www.plsok.com/wp-content/plugins/super-forms/uploads/php/files/3d4bb3d8f1397a4599e7286317eb9da2/99604866343.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8cca28b0b---dimeduzelifowikefunel.pdfIn PDF document text
    • http://mytmbc.org/fckimage/file/98730908694.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6193b13068---fitikobegokodopeb.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ff55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF55 5468 bytes
SHA-256: ce9c3d91f3fe920fff992e5dd1140934268ca62ff536443f3ed02283919d9a58
font_01_sfnt_off000111f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111F7 11292 bytes
SHA-256: 396ec57f2ed567b8472c3cc9edecd5833c504f82bd03d2063d1cd3b19bd0c93b