Malicious PDF — malware analysis report

Static analysis result for SHA-256 f423f8b7336552fe…

MALICIOUS

PDF

80.8 KB Created: 2021-09-09 15:03:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 26655850ad37f9f09db42a163228c8cd SHA-1: bfa2a9ab26240abb53aaad9baf4213b9d365a27f SHA-256: f423f8b7336552fe90eaa4516a257a8342bfc758908ad5d6c96b9d27885d3298
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to compromised WordPress upload storage and other disposable hosting. These links likely serve to redirect users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/16132f8365dbb6---87425265656.pdf In PDF document text
    • http://caythuocdangian.net/images/files/madulugazenij.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/b589c380c64ff01a2185e2fe9df1bec7/gajekofabewetopune.pdfIn PDF document text
    • https://manajrgvaaradhi.com/cms-uploads/files/xijijaronefizawizobafudok.pdfIn PDF document text
    • http://aliguoriarchitetto.eu/userfiles/files/xolizurasoxiwafewejo.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/dekuxolurekos.pdfIn PDF document text
    • https://kaimano.it/file/vigodusovuxuxek.pdfIn PDF document text
    • http://www.forteks.com.br/admin/ckeditor/ckfinder/userfiles/Images/57897020633.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613765a9e5701---60147296441.pdfIn PDF document text
    • https://noventa.cz/media/files/file/ruvup.pdfIn PDF document text
    • http://discus-rus.ru/upl/file/63414117668.pdfIn PDF document text
    • http://speckrepej.com/upload/file/nofagagevefozetas.pdfIn PDF document text
    • http://baby-daycare.com/uploads/files/202109030757349124.pdfIn PDF document text
    • http://educaholistica.com/resources/img/imagesck/files/54513683059.pdfIn PDF document text
    • https://ehlibeytalimleri.com/resimler/files/faradepigudizalanen.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/16136746f59401---geparojekaf.pdfIn PDF document text
    • http://exdebt.bg/userfiles/file/97564831436.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/3ff9de9986cf84cc2c6ebaa4f12c03bb/8585046724.pdfIn PDF document text
    • https://inprovitvenezuela.com/ckfinder/userfiles/files/74609350470.pdfIn PDF document text
    • http://toyotarent.tw/FileData/ckfinder/files/20210904_35ECD5E3AE56B88B.pdfIn PDF document text
    • https://udruga-invalida.hr/files/84117036327.pdfIn PDF document text
    • http://dywin.com/uploadfile/files/4586967083.pdfIn PDF document text
    • http://twtqedu.com/userData/ebizro_board/file/97636175219.pdfIn PDF document text
    • https://bk.knu.ac.kr/ckfinder/userfiles/files/wesizujonamavoratim.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=inotia+4+gem+mod+apkPDF 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_off0000d8d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8D2 17424 bytes
SHA-256: ed5513fcc011a5a0807d9e0c02dd2e62abd73f9089599554eaff5a33aed882bb
font_01_sfnt_off000105a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105A6 10540 bytes
SHA-256: 71d105eaaa264afdb10f0023b609ad52260fba2b3d7c823753006a3a4af1dcde
font_02_sfnt_off00011d7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D7F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1