Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1897dbfa369c350…

MALICIOUS

PDF

82.3 KB Created: 2021-09-23 07:02:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: f25d81fb9515666a2a77edaace4a174a SHA-1: a36d9b88b2db778f0bea2f9874a3ed701afeea75 SHA-256: c1897dbfa369c3509197a7a6e05ab40e934f78ee6f3d4f1f7c99c193fc13d1e4
156 Risk Score

Malware Insights

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

The file is a PDF document that contains numerous embedded URLs, many of which point to potentially compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically classifying it as a phishing trojan. The primary attack pattern involves luring users to click on these links, which likely lead to further malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://autohausnschmidt.de/userfiles/file/84407743917.pdf In PDF document text
    • https://hanakspotrebice.cz/eshop/ckfinder/userfiles/files/zidotaxiped.pdfIn PDF document text
    • http://wksx.top/images/userfiles/file/49493660606.pdfIn PDF document text
    • https://leresto-niort.fr/images/userfiles/files/46601509597.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/16130af1ae9b32---dematovaw.pdfIn PDF document text
    • http://taiwan-casters.com/userfiles/file/54695578259.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/161315173934df---84138505581.pdfIn PDF document text
    • http://fcgo.tw/uploadpic/files/resoriguwolavefafojosoji.pdfIn PDF document text
    • http://forti.in/userfiles/file/10011266725.pdfIn PDF document text
    • https://qualitygums.com/userfiles/file/zalurumapowuvonuf.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/16147dfe1ee85e---potakopoledekuxobi.pdfIn PDF document text
    • https://esofagopisa.it/userfiles/file/josovulesozawagof.pdfIn PDF document text
    • https://priscar.com/documents/files/sefemijikovakonu.pdfIn PDF document text
    • http://rungrawin-itt.com/userfiles/files/95397123656.pdfIn PDF document text
    • https://marblo.marblobaths.ph/app/webroot/img/files/dikekakexez.pdfIn PDF document text
    • https://confeccionesruiz.cl/UserFiles/File/59309532703.pdfIn PDF document text
    • http://zsdbiopharm.com/upload/files/94184401980.pdfIn PDF document text
    • http://dailyxedayhang.com/userfiles/files/79305915420.pdfIn PDF document text
    • https://drhuanghair.com/uploads/files/202109011900077859.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/6fn985jrbts3jhcag8l6im9f32/72367498089.pdfIn PDF document text
    • https://tuinvandecruys.be/file/24470705090.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=best+android+editing+apps+videoPDF 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_off0000de0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE0E 17444 bytes
SHA-256: a4c6ab6282aee9184c8ae4bc7a7f06a0bfa60f0d2463bc6a276b3aed0d0acb8f
font_01_sfnt_off00010b69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B69 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012380.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12380 10640 bytes
SHA-256: 9caebecf2cd54f1df849853173a63b442a6aec449cf487e9a1931411c99e26c0