Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fee257b158e97e2…

MALICIOUS

PDF

76.6 KB Created: 2021-09-13 16:29:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: dfc015dbee93a64d7a8d6b92d4c4c11c SHA-1: 4340fc4eb814505251c470002b6e913f3adac2cf SHA-256: 4fee257b158e97e25f5d0bc702e147e51b7bf88886770b569025425fc3d57a07
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to suspicious domains and are structured as potential download links for other PDF files, suggesting it functions as a link farm or downloader. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating the PDF is designed to host many links on disposable domains. While no scripts were explicitly extracted, the nature of the embedded URLs and the detection results strongly suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://estduquebec.com/scripts/php/xenocode/lib/ckfinder/userfiles/files/40470450531.pdf In PDF document text
    • https://sagarexpress.com/userfiles/file/fubibowilowide.pdfIn PDF document text
    • http://janjoling.com/public/ckfinder/userfiles/files/14329345632.pdfIn PDF document text
    • https://pfollowers.com/ci/userfiles/files/73937535154.pdfIn PDF document text
    • http://balogmihaly.hu/UserFiles/file/noxunepajojamumedamubokej.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161332e2fd3014---13176190461.pdfIn PDF document text
    • http://mstreatmentadvances.com/userfiles/files/75218014019.pdfIn PDF document text
    • http://farmandari-sarvestan.ir/images/news/files/jupefudilavaroxone.pdfIn PDF document text
    • http://huspanda.com/data/ckfinder/files/xibovirej.pdfIn PDF document text
    • http://prakseologia.eu/userfiles/file/vimunex.pdfIn PDF document text
    • http://ulsantour.com/FileData/ckfinder/files/20210901_5D4C4BF91753B847.pdfIn PDF document text
    • https://faktxeber.com/resimler/files/pigunugegesufurexudukiro.pdfIn PDF document text
    • https://ms2gacor.com/contents/files/45548556318.pdfIn PDF document text
    • http://geodeslaboratori.eu/userfiles/files/9604911659.pdfIn PDF document text
    • https://arrayamed.com/userfiles/file/selazene.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/eemacslnf19vh80v9cl0a69r34/kusasubitirowuvi.pdfIn PDF document text
    • http://vina2002.com/uploads/files/27743558054.pdfIn PDF document text
    • http://www.chiringuitomediterraneo.com/ckfinder/userfiles/files/79114144186.pdfIn PDF document text
    • http://globalnetworks.de/www.galabau-poscher.de/main/preview/ckfinder/userfiles/files/23840162644.pdfIn PDF document text
    • http://drivingtesttips.ie/fckeditor/userfiles/file/faperirevizobenanapoj.pdfIn PDF document text
    • https://flour.co.uk/ckfinder/userfiles/files/sogarin.pdfIn PDF document text
    • https://khotelmarket.com/FileData/ckfinder/files/20210904_80078F3BD6574E83.pdfIn PDF document text
    • http://laros.cz/UserFiles/file/dixupawukupukonofenuro.pdfIn PDF document text
    • https://pragatitic.org/ckfinder/userfiles/files/45574388403.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=where+can+i+watch+a+cinderella+storyPDF 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_off0000c5f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000de0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE0F 10660 bytes
SHA-256: f5a90cda15b23e8916ec59875c7ae62c165046ea69e1645642809d8294ed4ef1
font_02_sfnt_off0000f681.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF681 17576 bytes
SHA-256: ad0999e53d4fd4a0d4363bbc506e6d126390e0b0933e8c9b231a6c835bc61e4d