Malicious PDF — malware analysis report

Static analysis result for SHA-256 d9a2ab2ed541c95f…

MALICIOUS

PDF

87.4 KB Created: 2021-09-13 15:24:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d58f1ca84fa1b5e87d39d7c3a4b0fed1 SHA-1: b09fef33e1f945c18ce9613d500c1cba026e4617 SHA-256: d9a2ab2ed541c95ffb721befd68eec90d1321a39bc39e6d5b809b815888b0b86
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous external URIs pointing to potentially malicious or disposable domains. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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://cardion.dk/gfx/fckimages/file/jimodavo.pdf In PDF document text
    • http://faurerom.com/userfiles/file/rexapejorugakomijoto.pdfIn PDF document text
    • http://beamstraffic.ae/amb/userfiles/file/piwokikodubezu.pdfIn PDF document text
    • https://namdolove.com/FileData/ckfinder/files/20210904_CE4343CA80E7047D.pdfIn PDF document text
    • http://arredamentoambienti.it/img/file/41234554765.pdfIn PDF document text
    • http://tandartsindex.nl/images/uploads/21723878107.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/4bb4ae0889935881dd690a868ca4e1cf/zuleribafusipumorel.pdfIn PDF document text
    • http://www.sname.org.tw/sname/ckfinder/userfiles/files/93839677852.pdfIn PDF document text
    • http://shopgraeagle.com/ckeditor/uploads/files/13115454635.pdfIn PDF document text
    • http://studioscoponi.eu/userfiles/files/votamevitupowamus.pdfIn PDF document text
    • https://www.cylinder96.ru/admin/ckfinder/userfiles/files/35370565258.pdfIn PDF document text
    • https://jin-ji.com/upload/files/butitobu.pdfIn PDF document text
    • http://cloverdiamond.com/file/pejik.pdfIn PDF document text
    • https://egyiksem.hu/uploads/file/81236383168.pdfIn PDF document text
    • http://kingtonkatsu.com/uploads/files/poluwiwejofis.pdfIn PDF document text
    • https://grupahatak.pl/admin/_fck_files/file/wekinevuxo.pdfIn PDF document text
    • http://findmealocalpainter.com/insurazon/admin/userfiles/file/64172597322.pdfIn PDF document text
    • http://momsystem.ru/public/file/dumemitinovuj.pdfIn PDF document text
    • http://natpuedu.in/userfiles/file/1900540573.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613ecaaf5ac72---85967747876.pdfIn PDF document text
    • https://menlopark.com/wysiwygfiles/file/rumufenajoxubovumemanobud.pdfIn PDF document text
    • https://posh.hr/files/16694154231.pdfIn PDF document text
    • https://www.icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/28640891779.pdfIn PDF document text
    • http://akademibt.com/resimler/files/99907554117.pdfIn PDF document text
    • http://3sdent.com/upload/files/josajosa.pdfIn PDF document text
    • http://aktifimmo.lu/userfiles/files/vosumilupasovumek.pdfIn PDF document text
    • http://sistarelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/79291547180.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=speed+vs+time+graphPDF 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_off0000ef07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF07 10708 bytes
SHA-256: acfbeee0fafc43402a8c56d426cf6efd472599e03d079230376398f5135c8bc2
font_01_sfnt_off0001076f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1076F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F81 18760 bytes
SHA-256: 3597666d87de914e8d77eb4fde761f515609e52d30e0beeccd7af1b6988d5b6b