Malicious PDF — malware analysis report

Static analysis result for SHA-256 a238c4b8456cdcd0…

MALICIOUS

PDF

66.9 KB Created: 2021-05-13 07:33:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: b5167fe8ebf726448b5734d11c84af02 SHA-1: ce9e436145920e4e8cd5258c16e709a18bc2a7db SHA-256: a238c4b8456cdcd0039fbcb8e4e134bc6f3d98c1712e78f8192621186553d1fc
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to malicious content or phishing pages. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery mechanisms.

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://krisoc.ru/uplcv?utm_term=2018+calendar+pdf+telugu PDF link annotation
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/1dt0nvutan889et2uqblp0actl/18447832028.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/4dcf13772dd449962e2b0b32be969ec7/96058480617.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/f42e34a6819fd74a7e6a700cbe2497d3/kofotute.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/16094ecd3d97ec---25211296204.pdfIn PDF document text
    • https://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/4p5g8ojjej2qj7oma94igfglv1/14230396875.pdfIn PDF document text
    • https://pypconsultores.mx/userfiles/file/44665857483.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/1f947e47a0dfc658c1911f3f61610d79/69809314567.pdfIn PDF document text
    • https://www.acetechnology.co.in/wp-content/plugins/super-forms/uploads/php/files/a1h0739n8bro126scvcpmef8m5/turuxasunu.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079177eaa2a4---josijeraxazanavusisip.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/4ap4n4m5qshh01un31ncggmn33/31825316249.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/7c0cdea04825108d14e6a034cf9b2b62/21129319391.pdfIn PDF document text
    • http://nowyhotelik.pl/userfiles/file/vitod.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/60739875317.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160863c3ceaeb9---vagigi.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/3f4a13c12653b45005c368aa19f9a7ff/zaxugaxi.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608e175559055---vejapukurisizusetikiw.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c7e0d68329---73319050278.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/1d5c39121aa0a6621c8b6504a49c1847/65596301458.pdfIn PDF document text
    • http://novichiha.ru/pic/file/najuwufawujafaxo.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_off0000c961.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC961 5568 bytes
SHA-256: 70edf8f2452e00a953a44804e4a9cf5559ea5fe3c80aa6c7d7f1d2a4d8a7a206
font_01_sfnt_off0000dc65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC65 10080 bytes
SHA-256: fe3b1fa0fed4d51ac19c447b3fb201a8bea4d2d3d6aea98e80cd24dd26a2d66c