Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c86e013a242eb32…

MALICIOUS

PDF

71.5 KB Created: 2021-09-20 01:05:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: cce42ac6df7a64de16a79e89ca2b2086 SHA-1: 37b2c6bf44b4dd85eb7ba17e80fa36dacb7e6aab SHA-256: 6c86e013a242eb32944719ed80aa757f8d85b836ab4f8d8e4c9b04d02469f36a
126 Risk Score

Malware Insights

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

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a high number of embedded links pointing to various domains, indicating a link farm designed to redirect users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://duocvinhkim.com/userfiles/file/kudamuw.pdf In PDF document text
    • https://kildevangen.dk/files/33746498745.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/mobosewojirerav.pdfIn PDF document text
    • https://renault-service.com/userfiles/xelizuzuk.pdfIn PDF document text
    • https://hainutedecopii.eu/ckfinder/userfiles/files/dolufukibod.pdfIn PDF document text
    • http://mgtofubbq.com/uploads/files/93282460774.pdfIn PDF document text
    • https://n-vv.dk/userfiles/file/wiwijisete.pdfIn PDF document text
    • http://rc-modeller.se/images/file///18274910507.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613433f833248---wasumedekifovuvebuzo.pdfIn PDF document text
    • http://silverspringabw.com/uploads/files/retidujafenafebadipiwen.pdfIn PDF document text
    • http://0985028898.kad.tw/kads/ckfinder/userfiles/files/romakobozeroxavakixixuf.pdfIn PDF document text
    • https://artasedanasingaraja.com/uploadfck/file/dowabokekitajilixugus.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/fo4lpkpapvgpg6snl88bavtfuk/matekalaruwepigib.pdfIn PDF document text
    • http://ingpiazza.eu/userfiles/files/masuxopol.pdfIn PDF document text
    • https://mimpidia.com/contents/files/68592481025.pdfIn PDF document text
    • http://all-paca.com/ckeditor/ckfinder/core/connector/php/uploads/files/85173710546.pdfIn PDF document text
    • https://isleo.com/i_photos/file/58444546562.pdfIn PDF document text
    • http://esipro.be/userfiles/file/34561899564.pdfIn PDF document text
    • http://victoryelectricalsupply.com/ckfinder/userfiles/files/webafokefokabufipamij.pdfIn PDF document text
    • http://dallapietamarchisio.it/userfiles/files/lorojujazubugawekenibe.pdfIn PDF document text
    • http://tt-ural.su/admin/ckfinder/userfiles/files/39560271211.pdfIn PDF document text
    • http://gocep.org/data/userfiles/files/61953998877.pdfIn PDF document text
    • http://ecilingirler.com/resimler/files/nizonunadoxowesorevivoxum.pdfIn PDF document text
    • https://medicabg.com/uploads/wysiwyg/files/kiteximenedere.pdfIn PDF document text
    • https://paardenwelzijnscheck.nl/app/webroot/files/ckeditor_files/files/81111614323.pdfIn PDF document text
    • https://abandassociates.com/ckfinder/userfiles/files/rojadinirex.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=face+change+karne+wala+appPDF 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_off0000b867.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB867 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d079.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD079 15760 bytes
SHA-256: c4afc62d9680250828bc62cadb97a3a48b5b13f47619cf8f4529ba5730b23e2d
font_02_sfnt_off0000f878.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF878 10332 bytes
SHA-256: e62f042f96326088ed242840c382f464f172a0a6bfcedcabef7c0b47e43edbad