Malicious PDF — malware analysis report

Static analysis result for SHA-256 eb3f623c51dc93e1…

MALICIOUS

PDF

74.0 KB Created: 2021-09-18 14:19:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 2d32aaee266960d674f88300260d8f3a SHA-1: aeae04998d0ea50a2ad7af2d7ae1ebbd0f8edf7b SHA-256: eb3f623c51dc93e182e4c1f028e0b286fef20b770ba18ca0ad98321ccb39c775
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://yapluka-services.fr/userfiles/file/93726353512.pdf In PDF document text
    • http://wwstationery.com/files/file/95823247853.pdfIn PDF document text
    • https://traveletrust.com/basefile/traveletrustcom/files/kuserem.pdfIn PDF document text
    • http://dakdekkersindex.nl/images/uploads/ruvuvevoba.pdfIn PDF document text
    • http://yule-sign.com/upload/editor/file/20210903225035.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1614317622c414---35058015482.pdfIn PDF document text
    • http://karate-talence.com/newsite/userfiles/files/85537417459.pdfIn PDF document text
    • https://galedo.cz/www/data/cms_files/files/guzimovazokebufurubejomo.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/36165512f2233fd2e61ac4b023295166/lonopupikarujulirat.pdfIn PDF document text
    • https://machnhaduong.com/images/uploads/files/kegatobewozugasab.pdfIn PDF document text
    • http://www.salac.cz/ckfinder/userfiles/files/48120746103.pdfIn PDF document text
    • http://www.truca-taoules.com/ckfinder/userfiles/files/20778127150.pdfIn PDF document text
    • http://richardchong.com/userfiles/files/76469723719.pdfIn PDF document text
    • https://marblobaths.ph/app/webroot/img/files/vamabajigerifotopena.pdfIn PDF document text
    • https://aedwea.com/upload/foto/romurezigowobipinolilim.pdfIn PDF document text
    • http://showpalmedical.com/userfiles/bovulimapafatilajimotig.pdfIn PDF document text
    • https://kudamatsu.org/userfiles/file/zudivojemafavu.pdfIn PDF document text
    • https://rawoctane.com/uploads/file/68468399446.pdfIn PDF document text
    • https://k31szmq42-nu28.com/contents/files/88905007837.pdfIn PDF document text
    • http://www.pantonerestauri.com/ckfinder/userfiles/files/85140382327.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613f7c44ee0fa---84402160312.pdfIn PDF document text
    • http://patp1ryb.ru/media/file/zukotemofiwofufikilimusu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=diventare+root+su+androidPDF 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bec1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEC1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d6d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6D3 17208 bytes
SHA-256: 0cbcd31724adcf408dc833d53390b60987c3bf5b7a7135df1c6d75a621db800d
font_02_sfnt_off000102f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102F1 10364 bytes
SHA-256: 47f5eb06fc84e25f5e0ec433b5fc5379a0915f300a556df232ee1e926e02123b