Malicious PDF — malware analysis report

Static analysis result for SHA-256 31c8f1c76d08cb34…

MALICIOUS

PDF

99.9 KB Created: 2021-08-14 17:58:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 4b61641368a1198263f9467625e03548 SHA-1: 828bb0cc7d4f19bddcbdfbde6e14082b5a78f721 SHA-256: 31c8f1c76d08cb341e7c50ecee4757d4b3724326697a9f66977afb7811e1518e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external links pointing to disposable hosting, suggesting it's designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to create a link farm for SEO manipulation, likely to host phishing or malware download pages. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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=universal+termsrv.dll+patch+windows+10+2004 PDF link annotation
    • http://kamennykoberec.eu/editor_uploads/system/files/90346413697.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160725baaba15f---63704316099.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3a6b0b0174---62909511413.pdfIn PDF document text
    • https://rajakeempat.com/contents//files/jugevojuwames.pdfIn PDF document text
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/0946cdc98ff6b71fc89c92c759001aee/88686706781.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608700ba6946e---dunopinakebaxetaza.pdfIn PDF document text
    • https://mimpiindah1.com/contents//files/lalulik.pdfIn PDF document text
    • http://toeicspeaking.net/_UploadFile/Images/file/95272630973.pdfIn PDF document text
    • http://hncastlecable.com/d/files/54090582083.pdfIn PDF document text
    • http://www.llmhospital.com/www/js/ckfinder/userfiles/files/47462213390.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/9005668a9bfadd7e133efc41bb961ea8/tunirizugurak.pdfIn PDF document text
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/r6pbponfhv662g3s7hufv5svc6/nenusukiniruxifax.pdfIn PDF document text
    • http://dalnoboy.org/data/filestorage/upload/files/besubu.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/up1arqjvsqc644p4g3m6uejjca/wisixulirilojijadojulow.pdfIn PDF document text
    • https://lasvegasrebath.com/wp-content/plugins/super-forms/uploads/php/files/be4a58ff1a1b31c4d671707ff6ca39dc/58060131035.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/1609b2d47cd461---jolujowuzufotoduzetiluv.pdfIn PDF document text
    • http://stylekd.ru/files/24535274567.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c12f9dc3a34---11451790779.pdfIn PDF document text
    • http://oralrem.kz/ckfinder/userfiles/files/70608953286.pdfIn PDF document text
    • https://nguyenvanhuongloc.vn/app/webroot/files/images/pages/files/jumulubebo.pdfIn PDF document text
    • https://www.americansummercamps.com/wp-content/plugins/formcraft/file-upload/server/content/files/160870ee41bef3---97823142798.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_off000112af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112AF 24388 bytes
SHA-256: cc53dc72f29f8fae80b6b0cfe0c91664352efea35d13f2e567859a1f52f479c4
font_01_sfnt_off00014eab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14EAB 11376 bytes
SHA-256: bb3b5b546cb8b551bcab0aaeaef563c8fdd9359d6eba1601cea74b1d887a046e
font_02_sfnt_off00016977.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16977 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

Open this report in the interactive analyzer, or submit your own file for analysis.