Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb4b752a10f0aac2…

MALICIOUS

PDF

80.6 KB Created: 2021-09-08 19:35:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: d7056e218ca919f5ae451eee9bac4e99 SHA-1: 5b349264fc7b58180043a58eb2c08b753f51df88 SHA-256: bb4b752a10f0aac230ed12d0e76df1caba397580d59a7ecae7478f64066b373d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to PDF files hosted on various domains, indicating a link farm. Several heuristics suggest these links are part of a compromised CMS upload or disposable hosting, and the ML classifier strongly flagged it as malicious. The presence of external URIs and the nature of the link farm suggest an attempt to manipulate search engine results or distribute further malicious content, likely via spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://crc.creativechange.net/ckfinder/userfiles/files/xefixexetuguninuz.pdf In PDF document text
    • https://taechoclub.com/FileData/ckfinder/files/20210904_2D63369561839092.pdfIn PDF document text
    • http://www.superior-inkjet.com/login/ckfinder/userfiles/files/zegewisajipekanerupu.pdfIn PDF document text
    • http://ausafe.net/images/art/files/11674200477.pdfIn PDF document text
    • https://atrax.hr/files/defifipojuvarujo.pdfIn PDF document text
    • http://tochalco.com/uploads/files/sexazefagetowixupali.pdfIn PDF document text
    • http://mislenyiallatorvos.hu/userfiles/file/45540376420.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613221b5437f7---fozegajobezomizirofom.pdfIn PDF document text
    • https://serwisnawigacji.pl/userfiles/file/mavena.pdfIn PDF document text
    • http://sun-tes.ru/files/file/xotozutu.pdfIn PDF document text
    • http://dreiseengrundschule.de/files/wefonanen.pdfIn PDF document text
    • http://interreg-ipa-husrb.com/downloads/pavow.pdfIn PDF document text
    • http://cutyoursupport.com/userfiles/file/60984188837.pdfIn PDF document text
    • https://epgeptech.hu/ckfinder/userfiles/files/xegako.pdfIn PDF document text
    • http://ks-system.co.uk/ckfinder/userfiles/files/40366213745.pdfIn PDF document text
    • https://dallaslandscapedesign.com/media/files/wekanumilo.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/b9952de263f69153ffc56b5396c9b6d1/zoloredud.pdfIn PDF document text
    • http://baharev76.ru/userfiles/file/39292141595.pdfIn PDF document text
    • https://wanfutemple.urwaydesign.com/data/file/userfiles/files/vafinotazowimanamud.pdfIn PDF document text
    • http://werkkledingverkoop.nl/images/docman/files/99373905829.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161312d50d3f6b---xiwifagu.pdfIn PDF document text
    • https://zibarajabi.com/cache/fck_files/file/lupelexegula.pdfIn PDF document text
    • http://hoadondientu-ptp.vn/images/ckeditor/files/20246409669.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16138b99502432---8302993517.pdfIn PDF document text
    • https://foodvellythailand.com/upload/files/69528191621.pdfIn PDF document text
    • http://kapalishakti.com/ckfinder/userfiles/files/bedusel.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=doador+de+memorias+2+livro+pdfPDF 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_off0000d25e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD25E 20328 bytes
SHA-256: cb3fb0e272adb5b0060e7d996b20c230a638dc5fb52f800e3a1e654c45b99069
font_01_sfnt_off00010410.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10410 10644 bytes
SHA-256: e5244df5d54abc979b04864775683c57ee7a407bc9d3e190b61933376a4374d0
font_02_sfnt_off00011c76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C76 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1