Malicious PDF — malware analysis report

Static analysis result for SHA-256 23f0c9aee4791e0a…

MALICIOUS

PDF

77.4 KB Created: 2021-09-02 12:46:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9095ac63eb5fa30450cb494491f9b224 SHA-1: cd45b5368637b7869c7a2178035ca6f678c35c4a SHA-256: 23f0c9aee4791e0a2abf708b9045c256e69e59ee9d4f2a14008a9e77f8020845
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing pages or download further malware. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://bitree.com/ckfinder/userfiles/files/7510016037.pdf In PDF document text
    • http://zpkprzemysl.pl/ckfinder/userfiles/files/2888458374.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16107dd1da23e3---vovopematozozexi.pdfIn PDF document text
    • http://nitm.ac.in/nitmeghalaya/ckfinder/userfiles/files/14507523137.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/0vq8bc59ojir4fc871hbnmfrv0/dibidakorenedijurijatifen.pdfIn PDF document text
    • http://dailymaytrogiang.com/userfiles/files/zepefuxewawalesolilesilur.pdfIn PDF document text
    • http://nassagroup.org/app/webroot/js/ckfinder/userfiles/files/88844988699.pdfIn PDF document text
    • https://purevdavaa.mn/uploads/ckfinder/files/xagixedijobinapiw.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a106795b413---namonaxajobeviwenujulafi.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/16100305403fb7---1596851581.pdfIn PDF document text
    • https://burlingame.com/wysiwygfiles/file/kejedasavujubinaxi.pdfIn PDF document text
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a9d797852af---65937990899.pdfIn PDF document text
    • http://tangiahoang.vn/Images_upload/files/mupodusitobik.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609eaf9ce6e25---nidifarasu.pdfIn PDF document text
    • http://cachnhietwin.com/luutru/files/vologosuxebuju.pdfIn PDF document text
    • http://wo-kop.pl/userfiles/file/55064355655.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/5eb0165fb5752c0a43de301a1fc1d583/43920362168.pdfIn PDF document text
    • http://indianspringhomes.net/userfiles/files/didajifinijaponanovaga.pdfIn PDF document text
    • http://naasschoolofmotoring.ie/fckeditor/userfiles/file/92182607603.pdfIn PDF document text
    • http://supporttmes.com/clients/2/26/2647aeee05d38019bb2ff7af4ee9f9d5/File/47021115626.pdfIn PDF document text
    • http://df-foundry.net/d/files/saxifasemukipomusiv.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/16094baff97bbe---1354824435.pdfIn PDF document text
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609c6979c7edf---xefokidek.pdfIn PDF document text
    • http://mt-filtration.com/uploaded/file/149110120460befaaa0647d.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=cchf+disease+pdfPDF 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_off0000cbc2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBC2 17380 bytes
SHA-256: e7093b60753859acaabadb232210d4f58e1f2b82385bb353ac7b1a90651d08e0
font_01_sfnt_off0000f88d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF88D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000110a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110A4 10280 bytes
SHA-256: e07935864ec2a0d4934756fa68d0f857b96830b0cf002380a38321c1695da648