Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c71ce1dffdb138a…

MALICIOUS

PDF

94.0 KB Created: 2021-09-03 19:37:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 47c0695a83dd98f2b0c53a511830e6b6 SHA-1: f5b5899f73c5657c2a5bf212b0259e5348f23b51 SHA-256: 8c71ce1dffdb138a0805e47e819ff971b8156d31c5fd553ec1898b528acb9964
156 Risk Score

Malware Insights

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

The PDF contains a link farm, with many URLs pointing to potentially compromised websites or disposable hosting, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/dc757c3888645a9ce9426fd0ff5ad741/xivusesed.pdf In PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/e98fe80b33caa72b9d585d7620a6df01/kevoraguxev.pdfIn PDF document text
    • http://pitafest.com/clients/1/13/1337b7689af00ddd847345d48bd720ff/File/92543149892.pdfIn PDF document text
    • http://sutphinsgermanshepherds.com/clients/21958/File/sunufo.pdfIn PDF document text
    • http://gazosilikatnn.ru/uploads/files/39702265382.pdfIn PDF document text
    • https://equinox-e.com/upload/files/85297354168.pdfIn PDF document text
    • http://emiem.pl/public/upload/ckfinder/userfiles/files/madusukefok.pdfIn PDF document text
    • https://takitech.hu/userfiles/file/33426531719.pdfIn PDF document text
    • https://mgc.to/sites//web/upload/files/ropaluxug.pdfIn PDF document text
    • http://lysfyyy.com/upload/files/zewefixidekawidedi.pdfIn PDF document text
    • https://bmat.mn/uploads/ckfinder/files/62106788771.pdfIn PDF document text
    • http://mayjack.com/upload/files/zafilaj.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/44c4bd89f047634d767caf90e76351cc/36804313817.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607538422d1b6---9882449338.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1607829b9130b5---51192914938.pdfIn PDF document text
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ac0d004ece---23464929489.pdfIn PDF document text
    • http://orourkelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pusako.pdfIn PDF document text
    • https://isosklo.cz/uploads/manejilixerijevanibalu.pdfIn PDF document text
    • http://women-for-marriage.com/ckfinder/userfiles/files/31214519975.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16081827dafbe1---fuxofabuxojare.pdfIn PDF document text
    • http://www.tsahimmongol.com/uploads/images/files/zefurifivofipatowupazimoj.pdfIn PDF document text
    • https://dunaweb.co/bg_image/files/dixuterizako.pdfIn PDF document text
    • http://ambulanceservice.pl/userfiles/file/tojurasebob.pdfIn PDF document text
    • http://narcisse.sk/editor_uploads/files/32349771581.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=contrat+de+r%C3%A9exp%C3%A9dition+ou+de+garde+du+courrier+entreprise+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_off0001000d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1000D 11136 bytes
SHA-256: 3bfa9a731e42b2785fbfd1034b5d2ea2bad130b6285fed17ec2aa720a1d25d0e
font_01_sfnt_off000119b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119B5 20876 bytes
SHA-256: 50f85725303a409e26c601f0c887c085526e36729817c99a77c074bbae1a15da
font_02_sfnt_off00014f0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F0D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1