Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbf378fb87c3e27c…

MALICIOUS

PDF

67.2 KB Created: 2021-06-06 11:01:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 338667dcdd41c6f0414843413b6f8725 SHA-1: 0e657adcaa837ddd11f2cdd06241aa5d5f5e3fc3 SHA-256: cbf378fb87c3e27ccff87cc4602ac7f96339ca11c90d15ad6053336a829786c3
156 Risk Score

Malware Insights

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

This PDF document is classified as malicious by ML models and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The document body, though partially garbled, references 'Ejercicios acentuaci primaria pdf', a common lure to disguise malicious activity.

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://drafthe.ru/uplcv?utm_term=ejercicios+acentuaci%25C3%25B3n+5+primaria+pdf PDF link annotation
    • https://alihuata.com/userfiles/file/panoxokifaba.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/20bi7ov8m9ffurgrftl2sesj03/31336570622.pdfIn PDF document text
    • https://burmesecatclub.nz/wp-content/plugins/super-forms/uploads/php/files/47c6cac2a70d325df33643e86d984135/dumolarebifolaxelepiva.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160a53caa6c965---pefagunirajuneki.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a931e26d2f5---zenunebedutab.pdfIn PDF document text
    • https://www.mnspineandsport.com/wp-content/plugins/super-forms/uploads/php/files/7b131e7416e9ba14aa2fb56c797286bb/zuxugogosepejaso.pdfIn PDF document text
    • https://canvasations.com/wp-content/plugins/super-forms/uploads/php/files/vtlt8vouff3f6aetcqsfljbdr6/59812659930.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a2d6aab4efd---fudokitime.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1608e63df01453---99904874654.pdfIn PDF document text
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608923ab5a834---ponuw.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/df136eb652d4f515ac99f4fcd3d6aeb1/41232077884.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607694e8100ea---28807958458.pdfIn PDF document text
    • http://asja-doll.ru/userfiles/file/86760835342.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/texipuzadu.pdfIn PDF document text
    • http://pospatrans.cz/UserFiles/File/35294813361.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc008313543---momorakulozizedibevoxeb.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_off0000c708.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC708 5560 bytes
SHA-256: 5976998c7b1a8e677a747d87020265ccbb132e37577ca50509c70cfec1722a25
font_01_sfnt_off0000d9ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9AC 10948 bytes
SHA-256: e259deaf5a42c3b9d2225543ab65199f6134a2a490dd7f9e1b94e31a0a2549da