Malicious PDF — malware analysis report

Static analysis result for SHA-256 e87b455001357609…

MALICIOUS

PDF

74.6 KB Created: 2021-06-20 02:44:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: e26919c05e0879cf6501317cf7cd56ef SHA-1: b27453efd0ac922d1cf6a8c16baddae9f8df22c4 SHA-256: e87b4550013576092c727a2eb4deac2f11c986b864bed68f79a9f515e5e8be70
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm pointing to compromised WordPress uploads and disposable hosting, likely to host malicious content. The 'SE_CLICKFIX' heuristic confirms the document instructs users to execute commands, suggesting a social engineering attack to bypass security measures and download a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • ClickFix social engineering attack high SE_CLICKFIX
    Document instructs the user to press Win+R or paste a command into a terminal — consistent with ClickFix attacks that bypass macro restrictions by tricking users into running malicious commands directly
  • 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://osikovo.eu/webroot/img/content/files/denifed.pdf In PDF document text
    • https://europeancustomtailor.com/wp-content/plugins/super-forms/uploads/php/files/2e9098f9e47def0c7b3f7becdc1dd361/76429209476.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c6c417f6f9---12499382420.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/160846c1970c34---6580587723.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ac6a19c7571---wodagibipejupiwus.pdfIn PDF document text
    • https://condominiovillage.com/userfiles/file/likalosun.pdfIn PDF document text
    • https://cristalensi.com/public/File/44538961169.pdfIn PDF document text
    • https://mut-zur-veraenderung-hambuch.de/userfiles/file/kupoluvubid.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/338cca38b9c1354134c0347bc924bd09/zawefesuxivukovelagoz.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/a07bef6a62d858b2b6d8a576d176ccc7/58676626667.pdfIn PDF document text
    • http://sevgineslianaokulu.com/ckfinder/core/connector/php/uploads/files/32343240804.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0732d659c3---41901273518.pdfIn PDF document text
    • https://ecoretras.com/file/27599043521.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/ditukelatim.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=rufus+gpt+windows+10PDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d9a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9A8 5164 bytes
SHA-256: da6ce408c21304098f09b11ace20245ad2b51bc4c40dbf3daf2eb275744e02a8
font_01_sfnt_off0000eb79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB79 22108 bytes
SHA-256: 76563cfb8419bd3e2b34454796ee1e3baa80967a9025c97437c028dbbcd5e8d6