Malicious PDF — malware analysis report

Static analysis result for SHA-256 23cdf31cba8d737b…

MALICIOUS

PDF

80.8 KB Created: 2021-10-19 15:14:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 0239861a6d2ac3b5a7ad206450fc7d0d SHA-1: 86fe67ce665cf0aee48e02e53f91580417b7ef3c SHA-256: 23cdf31cba8d737b1490723a10d6ebd1ad14d3081d04955b59ff144f54dc2263
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The ML classifier and ClamAV detection strongly indicate maliciousness, with the PDF containing a link farm pointing to compromised CMS uploads and disposable hosting. The document body is heavily obfuscated, but the presence of numerous external URLs suggests an attempt to redirect users to malicious or phishing sites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirms the link farm nature, likely for SEO manipulation or to host further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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.
  • 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://svltv.in/userfiles/files/39398405490.pdf In PDF document text
    • https://stmarys-perthamboy.com/upload/File/polunutazokatodegu.pdfIn PDF document text
    • http://polkovnik.su/upload/file/dijivulajames.pdfIn PDF document text
    • http://ipublicity.cz/data/file/mijiwubezigigafewotivito.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16158b2450a028---9311876300.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/1f3cef6726faf88d3b2ea92a78f7ac39/forubezolaxadatetatinanu.pdfIn PDF document text
    • https://kolkatanagariksammelan.org/ckfinder/userfiles/files/jeputemupemetibemurusis.pdfIn PDF document text
    • http://rickgrisolia.com/userfiles/files/65174229262.pdfIn PDF document text
    • https://shunnasato.com/98209050161.pdfIn PDF document text
    • https://producedepot.us/userfiles/files/66955495911.pdfIn PDF document text
    • http://feminella.ro/upload/fck/11120878164.pdfIn PDF document text
    • https://www.la-providence-ehpad.fr/ckfinder/userfiles/files/41026050764.pdfIn PDF document text
    • http://resheto.ru/users_images/fck/file/jibafinevalegodipigafe.pdfIn PDF document text
    • https://facades-et-traditions.com/actualites/file/93848638064.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/d0dnjd1i3nohrgcgr6omdborb0/58046547743.pdfIn PDF document text
    • https://netshopnepal.com/userfiles/file/92368961025.pdfIn PDF document text
    • https://roundtable106trust.org/admin/uploads/file/66655006901.pdfIn PDF document text
    • http://jonme.net/ckupload/files/34200132271.pdfIn PDF document text
    • https://nusbetaja2.com/contents/files/94400740500.pdfIn PDF document text
    • http://matsonconstruction.net/userfiles/file/72189515715.pdfIn PDF document text
    • https://joebalogh.ro/imagini_ws/tezanawixozabikixa.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614932f356b5f---43038330457.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614879687abaa---20228386709.pdfIn PDF document text
    • http://feedproxy.google.com/~r/MbOu/~3/4dZi1sgP-vI/uplcv?utm_term=how+to+know+my+urn+number+in+aadhar+cardPDF 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_off0000d7f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7F9 17088 bytes
SHA-256: 7d79687f6f2f117e1e4f1cb95d2840973b782c5aa863538db4c598f3344c8ace
font_01_sfnt_off00010446.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10446 10944 bytes
SHA-256: c1c111ddaafdb8c2717241b9d558db89ac9e48939e79f137323cfe5a9dafcd55
font_02_sfnt_off00011d79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D79 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1