Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf16f41029631824…

MALICIOUS

PDF

69.6 KB Created: 2021-09-25 08:55:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 4bd61359e424e6b364e26c6f5be4cbf3 SHA-1: 4b1a159f392da460aaddb7736e29af559b0d7e7e SHA-256: cf16f41029631824888981ab838d45a47dec4fdd76f2fa6e16bffe3598ac8868
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to potentially compromised websites or disposable hosting, designed to redirect users to malicious content. While no scripts were directly extracted, the nature of the link farm suggests it's part of a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://stiff.pl/ckfinder/userfiles/files/lasogapidedimu.pdf In PDF document text
    • http://beauty214.com/uploads/files/202109180912317507.pdfIn PDF document text
    • http://kancelaria-perfect.pl/app/webroot/media/files/88043391502.pdfIn PDF document text
    • http://chandigarhdatarecovery.com/files/file/kusexadiwaf.pdfIn PDF document text
    • http://xn--q20b13r9leepaeb.net/upload/file/202109090033159595.pdfIn PDF document text
    • http://www.niceresidence.net/image/upload/File/12645996312.pdfIn PDF document text
    • http://suliaok.com/v15/Upload/file/202191195024503.pdfIn PDF document text
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16148fce5c8c07---xerijiwogikov.pdfIn PDF document text
    • http://www.gabrielamaciel.net/images/content/file/9213371409.pdfIn PDF document text
    • http://jedwines.com/cmsCart/upload/file/28078562333.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161330cad826b2---lilaliserezimegoli.pdfIn PDF document text
    • http://www.ettermanenterprises.com/ckfinder/userfiles/files/7152691656.pdfIn PDF document text
    • http://slkuang.com/v15/Upload/file/202193123056048.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/03131f0e0ad03f2c2304fb03416bd71c/nalijifuzofuzugikotupovus.pdfIn PDF document text
    • http://marasintl.com/public/ckfinderuploads/files/fivimonukakejaregi.pdfIn PDF document text
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/58lfklvme2bo6pkmd7jgds7uv4/dijitipamebalepebeguzuk.pdfIn PDF document text
    • http://ozdoby-betonowe21.pl/Upload/file/tufozekikesakoja.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141cac3c9c3b---kumiwe.pdfIn PDF document text
    • http://studiogaleazzo.eu/userfiles/files/mudadol.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/recir3pdi7cr0p6e63kq6lhctv/26221099847.pdfIn PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/fce08415226c83d55bca01098ffa4982/2792386184.pdfIn PDF document text
    • http://elateridae.com/images/FCKeditor/file/32885386392.pdfIn PDF document text
    • http://palmdale.thepokeluau.com/uploads/files/28651841398.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=idle+casino+mod+apkPDF 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_off0000b25c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB25C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA73 10520 bytes
SHA-256: 3f7e03a3ca247e2e5ad89f9100e2add6859b288cb1a2b4051a68153fe12a376f
font_02_sfnt_off0000e242.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE242 15248 bytes
SHA-256: b6aefb9e95ae7e7e0478a70d5008a4de54f3bb2e691f85d0acebf653eb3c9f78