Malicious PDF — malware analysis report

Static analysis result for SHA-256 cba1ff81090cc151…

MALICIOUS

PDF

74.3 KB Created: 2021-06-11 13:36:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: dfb2843390bce04285c43ac09f624a32 SHA-1: 3ba8833ce9945a7a325d98edd996d197b572ea15 SHA-256: cba1ff81090cc151df0f0754044b3d4e8de60e79f43ec4c2908da80b9c6f2d2d
156 Risk Score

Malware Insights

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

The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF contains numerous links to compromised WordPress sites and disposable hosting, suggesting a link farm used for distributing malicious content or phishing. The embedded URLs, such as https://inwebjor.ru/uplcv?utm_term=chart+of+active+passive+voice, are likely used to redirect users to further malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://inwebjor.ru/uplcv?utm_term=chart+of+active+passive+voice PDF link annotation
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bba4e834d9a---xutarexuperaxonenuda.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160a253f35ceb9---posufox.pdfIn PDF document text
    • http://fogathajtohirek.hu/fckfiles/file/78608497974.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/7bd7ef3e055456dd3494c0c94fb0f9af/81879143796.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16098aa9cc0b95---90731944234.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f3fd9d2478---savarazibu.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077c3424f246---soxesikunikoragisu.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/2fd55ae546131fc37e22cc5429a28458/80866187139.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071e0271837f---jiwibumurafigivoxa.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/23db35c56010ca1ec3c98da68a7d6459/zumufa.pdfIn PDF document text
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/dcvrrdh9201m3p7l2kedl920f4/bifutuxabotitevesoxoxamox.pdfIn PDF document text
    • http://luingpyrex.cz/foto/Image/file/fuguwib.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be6a0a24be7---3138358721.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/6g00cdrtlodufgschl5q4amj8h/topedugobikejifabugisun.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609d517f7e732---11376507048.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_off0000e69c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE69C 5036 bytes
SHA-256: b266b5db93b5508fba159517df6c6ae0d63d37e7f517af1ebdfaeb4193494be4
font_01_sfnt_off0000f7bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7BD 10760 bytes
SHA-256: 03c299d8024ef8f0fa7b1e24ea7530cc4b5a83149b6c97fbcaef1c205cca4531