Malicious PDF — malware analysis report

Static analysis result for SHA-256 932c422a0ac353d9…

MALICIOUS

PDF

70.4 KB Created: 2021-09-26 05:30:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b1f43cfc3febcd9e9ea6a6ed96bcf587 SHA-1: e2ad9f1f77d604547fedaa431ce5ea285899c206 SHA-256: 932c422a0ac353d9ca4cbdf77b28685d7649179938ebb0157f5809ea6b71ca6f
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to other PDF files hosted on distinct domains, indicating a link farm or redirection scheme. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic and the high number of unique URLs strongly suggest a malicious intent, likely to distribute phishing content or further malware. The ML classifier and ClamAV detection further support the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://byty-pardubice.eu/UserFiles/File/guraxazej.pdf In PDF document text
    • http://aa-nusd.jp/tileweposado.pdfIn PDF document text
    • https://www.profiemg.cz/upload/ck/files/zivosub.pdfIn PDF document text
    • http://farmina.ru/uploads/files/dabexoronokog.pdfIn PDF document text
    • http://tuivaivietnam.com/uploads/files/94182478656.pdfIn PDF document text
    • http://ricettebiagi.it/uploads/assets/file/48989349469.pdfIn PDF document text
    • http://lyzebrno.cz/userfiles/file/surubemerufuguta.pdfIn PDF document text
    • http://mcap.cz/images/uploadedimages/file/29282322663.pdfIn PDF document text
    • http://jiin-torng.com/uploadfiles/20210904181009.pdfIn PDF document text
    • http://antonio-pelella.eu/userfiles/files/46147813952.pdfIn PDF document text
    • http://www.miyadenthai.com/image/upload/File/xexofusotikagekafi.pdfIn PDF document text
    • http://baovekhucongnghiep.com/upload/files/jagapuda.pdfIn PDF document text
    • https://pisausakti.com/contents/files/taxadigatavuzadu.pdfIn PDF document text
    • http://fobosgrunt.ru/files/ckfinder/files/fuxatufito.pdfIn PDF document text
    • http://ngocphuocjsc.com/public/default/ckeditor/files/96244107763.pdfIn PDF document text
    • https://manusingh.org/scgtest/eec-new/codelibrary/ckeditor/ckfinder/userfiles/files/42008707503.pdfIn PDF document text
    • https://xulynuocphangiathinh.vn/images/pic/file/xezuxanajukagemumepuve.pdfIn PDF document text
    • https://nbcmedia.vn/ckfinder/userfiles/files/rusisujef.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bd2bbef7d9---74701914450.pdfIn PDF document text
    • http://swaptoys.org/ckeditor/uploads/files/roxibeniwoge.pdfIn PDF document text
    • http://tangiahoang.vn/Images_upload/files/kasakonasiba.pdfIn PDF document text
    • http://ewhamd.net/upFiles/ckeditor/files/2469851213.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/161476a0b57c92---bujudekukojazom.pdfIn PDF document text
    • https://nissanzorba.ro/ckeditor/ckfinder/userfiles/files/72421822610.pdfIn PDF document text
    • http://dailymaytrogiang.com/userfiles/files/tonimelo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=send+email+kotlinPDF 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_off0000b057.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB057 10308 bytes
SHA-256: 9247a7d7138ddcf87acc852651fe3b02e7ee58ff2ab90f25686b8ed518c89b7a
font_01_sfnt_off0000c787.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC787 17012 bytes
SHA-256: 661f72e7270de23a9f5264fbdefdddc0b7621c9b5922aa61b39962b6a19b58f4
font_02_sfnt_off0000f3f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1