Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb36ec0cc4a90933…

MALICIOUS

PDF

75.1 KB Created: 2021-09-14 01:22:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: fdb3c76fd68bfd53a8ad1ad569c8b7cf SHA-1: ca8044579d7a4c1d2aba667ea6709c92275d6111 SHA-256: cb36ec0cc4a909336ff19db88cf97022faa331cab6ca501fa1490dfa42234713
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://rowadalbyt.com/userfiles/files/79597379555.pdf In PDF document text
    • http://paillasse.hu/userfiles/file/37573199982.pdfIn PDF document text
    • http://mobilahomedesign.com/userfiles/files/54630191942.pdfIn PDF document text
    • http://historico.uts.edu.co/portal/app/ckfinder/userfiles/files/bobajasufomaj.pdfIn PDF document text
    • http://breakevenpoint.pl/uploads/editor/file/jedusaxawebugovuxepejiz.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613dc2216b4c1---lafikatomajapijig.pdfIn PDF document text
    • https://www.vpn-solutions.com.pe/ckfinder/userfiles/files/23990033053.pdfIn PDF document text
    • https://asiquim.com/ckfinder/userfiles/files/57235021660.pdfIn PDF document text
    • https://yuanfuconstruction.com/ckfinder/upload/files/93955057013.pdfIn PDF document text
    • http://el-master.ru/userfiles/file/ranotebuniz.pdfIn PDF document text
    • https://chuyennhakienvangvn.net/upload/files/kipigegusefena.pdfIn PDF document text
    • https://ssekolkata.com/ckfinder/userfiles/files/50462226098.pdfIn PDF document text
    • http://gusanhightec.com/userData/board/file/5768786053.pdfIn PDF document text
    • http://patroha.hu/file/44061935141.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/62629659822.pdfIn PDF document text
    • http://marleenjansen.nl/images/uploadfiles/gaguk.pdfIn PDF document text
    • http://acrclubinversores.com/files/galeria/files/14171811305.pdfIn PDF document text
    • http://amirafouad.com/uploaded_files/file/sutejolimatez.pdfIn PDF document text
    • http://jamalcar.com/userfiles/file/32097048624.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-9-1/20210901225910201508.pdfIn PDF document text
    • https://rcvizovice.cz/ckfinder/userfiles/files/81019370406.pdfIn PDF document text
    • https://99shayari.in/userfiles/files/wisizasazomonorezijux.pdfIn PDF document text
    • http://stitesattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nodegazuxizisefix.pdfIn PDF document text
    • http://archidaldegan.eu/userfiles/files/63443997695.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+cast+from+vlc+to+android+tvPDF 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_off0000c401.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC401 10648 bytes
SHA-256: 4513056b471495d97a250aeebdf8419f35459785ba601d65f251112078d05b81
font_01_sfnt_off0000dc61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC61 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f473.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF473 16308 bytes
SHA-256: a316653bb00fe9a0479f9fcb18f39845eb9995a092a1fedead6d6f21a3e42e6f