Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ffcb1808faf6345…

MALICIOUS

PDF

70.7 KB Created: 2021-10-01 10:02:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c44a0e5d8a11bd2b1a4c70946bc77430 SHA-1: dfa1d89f6a1ed1760e4a626fe99d5c08b127f74a SHA-256: 8ffcb1808faf6345ab836ee62e1dbbc89e12697fc6ac21a5997ef86c3096c6dc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Numerous URLs extracted from the document point to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. The PDF structure and embedded URLs are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://krisoc.ru/uplcv?utm_term=hub+44+movie+ala+vaikunthapurramuloo PDF link annotation
    • https://grupo-kayros.com/userfiles/file/34315563019.pdfIn PDF document text
    • https://lingchuanfloor.com/app/webroot/userfiles/files/gelemuzoxuwatinodurokaban.pdfIn PDF document text
    • http://streathamtaxi.com/survey/userfiles/files/20563801692.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16138751bbca90---76573125547.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/25421527008.pdfIn PDF document text
    • http://creativetechno.in/userfiles/file/10962180200.pdfIn PDF document text
    • http://morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/161480987e3fef---96093991670.pdfIn PDF document text
    • http://champaigncursillo.com/userfiles/file/podovofeluvivisa.pdfIn PDF document text
    • https://nexapos.com/upload/files/foxugore.pdfIn PDF document text
    • http://swapnakoodu.com/fck_uploads/file/52747785106.pdfIn PDF document text
    • http://baikalspring.ru/ckfinder/userfiles/files/89419456818.pdfIn PDF document text
    • http://goghepcacloai.com/media/ftp/file/64363529429.pdfIn PDF document text
    • http://fixafilm.se/userfiles/file/gileralisufakozadutami.pdfIn PDF document text
    • http://siciny.pl/userfiles/file/23088465803.pdfIn PDF document text
    • https://www.esfa.bg/root/ckfinder/userfiles/files/goraxunojuxeza.pdfIn PDF document text
    • https://likeevent.it/writable/public/userfiles/file/vujoziribalaki.pdfIn PDF document text
    • https://iphone-odklep.si/vsebina/46036664990.pdfIn PDF document text
    • http://sm300159.agchost.com/userfiles/files/viduxexovisot.pdfIn PDF document text
    • https://bnbcostaverde.it/userfiles/file/vujigisijudosebegutupep.pdfIn PDF document text
    • http://mdsalon.ru/img/lib/file/50433104164.pdfIn PDF document text
    • https://k-newsletter.com/ckupload/files/rolute.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/16143a7898bd6d---95771940839.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_off0000b099.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB099 10816 bytes
SHA-256: ff8dd1bfa46f1e3f3cf07f0d0603768faffc7956bca71be7a7d992ca305d231a
font_01_sfnt_off0000c911.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC911 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e123.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE123 16408 bytes
SHA-256: 2faeaf9c97c99ba51e1167e9c9de04d4f294f4235de4b1bc6772cf12b555ee9f