Malicious PDF — malware analysis report

Static analysis result for SHA-256 b458ba6e3878b15e…

MALICIOUS

PDF

79.6 KB Created: 2021-09-12 23:47:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: b8c76cedfd660f5dd13fc6e446239a2a SHA-1: 1c795eeefa7d6607400481c7835ac9ab346a0ebc SHA-256: b458ba6e3878b15efe1405b66a8ade0f7946b035c61bb3f96603938308c4c2e4
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF contains heuristics indicating it is a malicious phishing document designed to trick users into installing software. Specifically, it uses a 'Browser extension / update installation lure' and a 'Visual download / call-to-action button lure'. While no scripts were directly extracted, the ML classifier and ClamAV detection strongly suggest malicious intent, likely involving the download and execution of a second-stage payload via embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 http://theexplorerthai.com/userfiles/files/53329182013.pdf In PDF document text
    • http://laureysnv.be/uploads/files/16785357136.pdfIn PDF document text
    • http://nail-free.com/ckfinder/userfiles/files/biwegotopevodowokir.pdfIn PDF document text
    • http://xahscw.com/userfiles/file/15569988761.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/gugexevosow.pdfIn PDF document text
    • http://sky1981.com/asset/uploads/files/8034943584.pdfIn PDF document text
    • http://bradzo-ep.com/uploads/files/nowamupe.pdfIn PDF document text
    • http://arcdesantmarti.com/biocop/Images/images-editor/file/51591336882.pdfIn PDF document text
    • https://minlinart.com/archive/upload/files/kuzejolivizavowifure.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/1omjd7ba90uo5hvbircofgh5co/57979281546.pdfIn PDF document text
    • https://matras-matrasych96.ru/admin/ckfinder/userfiles/files/besonizexuwusazenoso.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9e8546875---nurixadobepes.pdfIn PDF document text
    • http://brainbond.ro/userfiles/file/tokoritatumirelixeb.pdfIn PDF document text
    • http://czerwoneiczarne.pl/files/file/61475719502.pdfIn PDF document text
    • https://eqonetech.com/upload/userfiles/files/42669960237.pdfIn PDF document text
    • http://everintelconsulting.com/upload/file/202109090327256547.pdfIn PDF document text
    • http://kanoonkaraj.ir/dbmanager/filebank/htmlgallery/file///zuzumafobunumagaferitutag.pdfIn PDF document text
    • http://studioarchoggianiepartners.it/userfiles/files/86856498404.pdfIn PDF document text
    • http://galeriejacqueselbaz.com/userfiles/file/korixometerofezipenuroz.pdfIn PDF document text
    • https://laatjehuisweerstralen.nl/upload/file/92516396965.pdfIn PDF document text
    • http://year-c.com/upload_fck/file/2021-9-6/20210906212404868275.pdfIn PDF document text
    • http://spharma.ua/files/file/pofozozelapigivi.pdfIn PDF document text
    • http://kindergartenhelden.at/upload/file/73277382173.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=macromedia+flash+player+androidPDF 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_off0000d388.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD388 10896 bytes
SHA-256: a83ce5f2cb5e0affb586197bafb643b4bf9908985a9a01bd900fe40e30e1ff84
font_01_sfnt_off0000ec87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC87 17384 bytes
SHA-256: edc4dd82f0c89cc0a1b90a6f94a30d44ef9be0e1df297473d52cdf5f20c4c951
font_02_sfnt_off00011938.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11938 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1