Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9e0cd5b0cb76195…

MALICIOUS

PDF

95.3 KB Created: 2021-08-16 06:53:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: f217e4560e2adf01930b0b40e706d0d1 SHA-1: a2c80888ece51b9b469cbbc6af089d9a0a8778c5 SHA-256: b9e0cd5b0cb76195e9978b6bff0df95b46eaa185d501135d201b4d0185408e9a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, directing users to numerous external URLs, some hosted on compromised CMS upload directories. The presence of multiple links and the use of disposable hosting suggest an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 http://ruishikaishi.com/upload/content/files/2021/06/20210619023637.pdf In PDF document text
    • http://www.redactordecontenidos.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a156b4611ff---91644041513.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/160af724322765---33718336977.pdfIn PDF document text
    • http://zonweringnederland.com/ckfinder/userfiles/files/82215394816.pdfIn PDF document text
    • http://kuehllawpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gorawujebojezo.pdfIn PDF document text
    • https://damiel.eu/userfiles/file/26816295123.pdfIn PDF document text
    • http://www.southforconstruction.com/frontend/web/ckfinder/userfiles/files/13828220742.pdfIn PDF document text
    • https://irrisyst.eu/files/file/nunixipiwosine.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16084500ca9658---17567790639.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/1a4856214232d2e26bc6b3e9cea4e354/24775459367.pdfIn PDF document text
    • https://foodsafebox.com/ckfinder/userfiles/files/joribe.pdfIn PDF document text
    • http://library.nesdb.go.th/ic/admin/ckfinder/userfiles/files/kefetomejokivelajozajaru.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f8c08490332---34841922050.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6d0d548ebf---sulaliz.pdfIn PDF document text
    • http://sosonomo.com/ckfinder/userfiles/files/49153813142.pdfIn PDF document text
    • http://pizzeria-millemiglia.de/app/webroot/img/editor/file/65858545974.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bb591c39d4a---97276376265.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/22651535041.pdfIn PDF document text
    • https://laihouston.com/wp-content/plugins/super-forms/uploads/php/files/45f4560ca37afc20ccf7ada7c38590ba/90495878545.pdfIn PDF document text
    • http://eksan-ltd.com/userfiles/file/gefojanog.pdfIn PDF document text
    • http://skybuildinfraprojects.com/uploads/78149367920.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/95d2d9535801796f0748ec070c71f0b2/70960295563.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=book+called+the+art+of+invisibilityPDF 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_off00010e16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E16 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012628.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12628 17696 bytes
SHA-256: a07d98b0af735c51b9831f8526eb3cd1efa11e9cad7545d17a0fad10a04f6ca5
font_02_sfnt_off0001544c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1544C 11040 bytes
SHA-256: ab20a1bf508c3ab3d0201e109ebd5ffe344a18709a6a0a7387966c7dbe76c5c0