Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8ddafc78fdc2678…

MALICIOUS

PDF

68.3 KB Created: 2021-09-30 17:00:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: e98377b072f0f4dc9e54fb98742c2221 SHA-1: 584b6de28366144115cd7dbe2cc8252e6a61ced5 SHA-256: f8ddafc78fdc2678714ad7ae468b2aa5bad9df7b0e4e7b000e0200523cfd7465
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to various domains, many of which appear to be disposable or compromised hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document is designed as a link farm on disposable hosting, likely to distribute malicious content or conduct phishing attacks. The presence of a URL with 'nox+cleaner+download' suggests a lure related to software downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://oniceh.ru/uplcv?utm_term=nox+cleaner+download PDF link annotation
    • http://csa.china-led.net/static/editor/ckeditor/ckfinder/upfile/files/17467344821.pdfIn PDF document text
    • http://sabaispa.net/userfiles/file/79982403368.pdfIn PDF document text
    • http://ud2-140.com/files/41782149560.pdfIn PDF document text
    • http://xmzhj.com/UserFiles/file/94955869315.pdfIn PDF document text
    • http://soleilboo.com/images/uploads/files/konozijipofexojakubosaki.pdfIn PDF document text
    • http://enslev-anlaegsservice.dk/userfiles/file/98513711742.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613da319cb2a7---37389527701.pdfIn PDF document text
    • https://www.cylinder96.ru/admin/ckfinder/userfiles/files/goxepixezen.pdfIn PDF document text
    • http://xedaptheduc.net/app/webroot/uploads/files/xatenadeluzojijofozezata.pdfIn PDF document text
    • https://truongthanhco.vn/webroot/img/files/67824019801.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7f99e3a38---logipirerabeselewivozaw.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16150ecfdc4bd4---jujezadodukixejapulixikub.pdfIn PDF document text
    • https://augsburger-dartliga.de/uploads/file/dovomovepurijivodize.pdfIn PDF document text
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/5071f6e53fc0052518472239f2a14fb8/26070888721.pdfIn PDF document text
    • https://pmsp-me.com/userfiles/files/71758865544.pdfIn PDF document text
    • https://artistaone.co/userfiles/files/natobularuduwa.pdfIn PDF document text
    • https://stotex.rs/files/xuduzerawelevewa.pdfIn PDF document text
    • http://vietsonplastic.com/uploads/userfiles/file/lemozujedop.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/4f69f46fb849977cb216d1b49f765c89/renofinarazibakomowomewo.pdfIn PDF document text
    • https://saintarseny.ca/sites/saintarseny.ca/files/file/31907983977.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/16155a45286794---81551987064.pdfIn PDF document text
    • http://csp.hu/editor_up/17702583844.pdfIn 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://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_off0000ae53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE53 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c66a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC66A 10168 bytes
SHA-256: 5ea3139ecf62663f5c56ca5241efdf445977b5ba5e489c323c98ff241ef52a60
font_02_sfnt_off0000dd56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD56 15288 bytes
SHA-256: 1e0908a448c8268975e1bd3d18ddfa3935e56881b8705f8e621e1cde72a4ca76