Malicious PDF — malware analysis report

Static analysis result for SHA-256 492ad49251685d8f…

MALICIOUS

PDF

81.7 KB Created: 2021-09-19 15:56:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9f4db37d2a71a31cf042a17d9b6a3fcf SHA-1: ae40a723c0b825e372da4a3cd60db0be605e36bf SHA-256: 492ad49251685d8fb2c3d1553e3d504864802b70e62dd04f9c66a82ec5e9e3ba
126 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous embedded URLs pointing to external PDF files, suggesting a link farm or redirection mechanism. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM further supports this, indicating a pattern of disposable hosting for these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9867

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://karaokejdi.com/ckfinder/core/connector/php/upload/files/90317266091.pdf In PDF document text
    • http://giadinhlaurenso.org/upload/files/45239172926.pdfIn PDF document text
    • https://www.icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/84927444270.pdfIn PDF document text
    • https://jechrina.gr/FCKeditor/userimages/file/fujipemotuxuxokijelowive.pdfIn PDF document text
    • http://www.tempshift.com/app/webroot/files/uploadimagesfile/23895531118.pdfIn PDF document text
    • http://chpcentre.com/files/file/18680946025.pdfIn PDF document text
    • http://cambridgekapurthala.com/damana/userfiles/file/jixuv.pdfIn PDF document text
    • https://eguiders.com/uploads/87413618331.pdfIn PDF document text
    • http://www.sictombbi.fr/ckfinder/userfiles/files/99546770842.pdfIn PDF document text
    • https://ph2020.org/FCKeditor/file/nagafevasojubopinofa.pdfIn PDF document text
    • http://apexnepaltravel.com/userfiles/file/73560929995.pdfIn PDF document text
    • http://humanitool.ru/userfiles/file/topudupidusimigepemeruw.pdfIn PDF document text
    • https://lexconsulting.ro/webroot/files/media/penubitosovuxewafexumo.pdfIn PDF document text
    • http://hytechplus.com/userfiles/file/witosogeg.pdfIn PDF document text
    • http://sujitonweb.com/userfiles/files/kipalaramopozizifuli.pdfIn PDF document text
    • http://samtekelektrik.com/files/71062262770.pdfIn PDF document text
    • http://faisaltowel.com/survey/userfiles/files/javugukaretefafosakeg.pdfIn PDF document text
    • http://yhbinternational.com/userfiles/file/defigigamumimosufuf.pdfIn PDF document text
    • https://hoavily.com/uploads/files/jowegagekakutakenu.pdfIn PDF document text
    • https://ruh-center.ru/userfiles/file/tefavikavitamonal.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/b05cab0acce048e56e5c84eec42dc788/43461310505.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16139dab7d7cde---gofala.pdfIn PDF document text
    • http://vencedor.coop/images/admin/file/jeponedimor.pdfIn PDF document text
    • http://namhungholdings.com/uploads/ckfinder/files/fiwodalugurexokovemibobi.pdfIn PDF document text
    • https://alshuka.ps/ckfinder/userfiles/files/53741492021.pdfIn PDF document text
    • http://stellar-toys.com/ckfinder/userfiles/files/6531939084.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=nitro+code+freePDF 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://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_off0000e10a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE10A 18608 bytes
SHA-256: 7aad8abe52c945fe6528994519f7d98362afb19d457df3ed6958083b9fa64cb0
font_01_sfnt_off000110f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110F7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001290d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1290D 9964 bytes
SHA-256: c32e043660fd2a8b7993d84a5cd038874bdbe2be3e7c50454d239facaafcf96b