Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb56df7b4f1d51fb…

MALICIOUS

PDF

81.6 KB Created: 2021-09-15 17:25:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 767036e14b39805d48d1d100cfcf1a92 SHA-1: b6d7578d4f60b3c4d9b2b55f56a50dcd203b129c SHA-256: cb56df7b4f1d51fb449f5febd51de8eb52159d11fa503b4e8efe75ed849f4dd4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document's primary purpose is to host a large number of links to other PDFs, likely for SEO manipulation or to distribute further malicious content. While no scripts were explicitly extracted, the presence of numerous unknown URLs points to a distribution or redirection mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://cuacuonnhaxuongbinhduong.com/upload/files/60688650613.pdf In PDF document text
    • http://xn--12cf1djdb6cbcafdbu1f1cudgcc8am4wf7htgd9de.com/ckfinder/images/files/sisaxapasenij.pdfIn PDF document text
    • http://capitolmetrophysicaltherapy.com/userfiles/file/76303876129.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/lilamobaganeputazeliwuk.pdfIn PDF document text
    • https://eastmangroupllc.net/ckfinder/userfiles/files/gabelefoxiwedokux.pdfIn PDF document text
    • https://ldcpc.com/ckfinder/userfiles/files/9312499600.pdfIn PDF document text
    • https://x-software.cz/data/file/88710935479.pdfIn PDF document text
    • http://lsbwg.com/ckfinder/userfiles/files/20210907/1523185499.pdfIn PDF document text
    • http://dhleisure.com/ckupload/files/wejawajefekekewezu.pdfIn PDF document text
    • http://devveb.net/userfiles/file/918773687.pdfIn PDF document text
    • http://centonze-vini.com/userfiles/files/zodububeborafivofajoza.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139d4d5be139---44334887665.pdfIn PDF document text
    • http://ksiclubcom.ksiclub.org/svnprojects/DHD/Source/images/files/jipotazewa.pdfIn PDF document text
    • http://fulns.com/uploadfile/fckedit/file/1630553769NzCc.pdfIn PDF document text
    • http://dream-mebel.com/pic/file/pevufenezufuliwulalati.pdfIn PDF document text
    • http://project-lovcen.me/userfiles/file/fejuriwotu.pdfIn PDF document text
    • http://chinhsuasolieu.com/media/files/80475309118.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/09bd3ae6fa799436e575b0d7cd321004/desuj.pdfIn PDF document text
    • http://ladna.pl/user_images/file/wagumeketu.pdfIn PDF document text
    • https://askisan.com/upload/ckfinder/files/puzoxerizomarevaxokoguzaj.pdfIn PDF document text
    • http://caycanh.vn/images/fck/file/mokibupavolakiwaz.pdfIn PDF document text
    • http://aquaclub.hu/userfiles/file/modumaradupuwu.pdfIn PDF document text
    • http://skupka23.ru/upload/m/gomumovewawuzejezukiwo.pdfIn PDF document text
    • http://hoadon-dientu.net/images/files/87952365334.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=harry+potter+1080p+downloadPDF 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_off0000dbe1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBE1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F8 10696 bytes
SHA-256: 786d49e64ae133ce4bf9e802c1527902b4c5f7c28ae2f4ce4ad42656867e6140
font_02_sfnt_off00010cb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CB3 17248 bytes
SHA-256: c8350e8dd6f14e0f25227f65269550cbe32855b27384be5a80c2275118dd3a94