Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b4ec2a4e109c8af…

MALICIOUS

PDF

100.6 KB Created: 2021-08-08 09:44:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 9dc15e36f7d9e7bc9693697382f017cd SHA-1: 9ab5d3fffadd029bbfa8537ce1c8a9e37dab6d89 SHA-256: 6b4ec2a4e109c8af63f2c00c666ec96deb862993f8e8a61acf45dcab7f546c8e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to compromised WordPress upload storage and other disposable hosting sites, suggesting it functions as a link farm to distribute malicious content or phish users. The PDF structure and embedded URLs point towards an attempt to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://18554080.com/userfiles/file/85824481320.pdf In PDF document text
    • http://montaze.org/democms/userfiles/file/bakaropuxikolovomotefov.pdfIn PDF document text
    • http://hondatayho.top/img-ngocbao/files/4619228063.pdfIn PDF document text
    • https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/fda97356dfe076da1b71a38d681e91c1/wosibas.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/12279387950.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/bixufubazagu.pdfIn PDF document text
    • http://arisutour.com/ckupload/files/vatoredam.pdfIn PDF document text
    • https://vegas-shop.net/uploads/files/46519491175.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/4f14cb99152354b532808bd34f62c5a6/giruzuz.pdfIn PDF document text
    • https://www.willmarshelter.com/ckfinder/userfiles/files/womikifesumumaze.pdfIn PDF document text
    • http://ferrogep99.hu/static/media/file/vareporidon.pdfIn PDF document text
    • http://blackshirts1962.com/clients/f/f2/f245580d3072b78cda2271cf7a7e3f61/File/38182683760.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a273d5ce2a2---jamuditorefig.pdfIn PDF document text
    • http://urduhadith.org/survey/userfiles/files/bibenanikuk.pdfIn PDF document text
    • https://serwisnawigacji.pl/userfiles/file/22193360058.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/83be60cff70b33be2bc49e2b86f3da28/segomuf.pdfIn PDF document text
    • http://taikenplan.jp/ckfinder/userfiles/files/10275576124.pdfIn PDF document text
    • http://mai-colle.jp/userfiles/file/7942854589.pdfIn PDF document text
    • http://www.taimaobi.com/admin/ckfinder/userfiles/files/folubukogejejejudobimem.pdfIn PDF document text
    • http://interstyle.org/content/xuploadimages/file/liganejanevuvupojata.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1606f29a411dd2---41392182082.pdfIn PDF document text
    • https://berbagiangka.com/contents//files/fokukaroguji.pdfIn PDF document text
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608f3172b3316---wigawuziripozaramegoba.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/bk1aa06k3jn6ahjndrbkhon182/rupuvekisifix.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=problemas+de+concentracion+de+porcentaje+en+masa+y+volumenPDF 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_off00011d19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D19 19148 bytes
SHA-256: 50080fd47d33737acf5ccc204106a2abb494e9348e5301e59dda25c269403373
font_01_sfnt_off00014f0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F0A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016721.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16721 11224 bytes
SHA-256: a64df263503a2f31a7e8c3ae77d15e6d9d25d41cb2efa0c6085b5ed21668c52f