Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef20959b1d056e3e…

MALICIOUS

PDF

73.6 KB Created: 2021-06-11 05:41:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 07469c9f706eb6499b94d08bcdd47dc5 SHA-1: 8f5f185ee568ee34d49dfad7960a06fe426a2a17 SHA-256: ef20959b1d056e3e1a0f823149e331bad30ba5d0e93eafd1d78186894bfc852e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links pointing to compromised websites and disposable hosting, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, appears to be related to 'one step equations word problems worksheet', a common lure for educational-themed phishing. The presence of embedded URLs and the overall structure strongly indicate an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9817

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://drafthe.ru/uplcv?utm_term=one+step+equations+word+problems+worksheet PDF link annotation
    • http://0vote.com/ckfinder/files/16848320064.pdfIn PDF document text
    • https://www.oneirishrover.com/wp-content/plugins/super-forms/uploads/php/files/5f8d77b1fe825b5643fea1ec9cfb177c/19024176921.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160bd8b6eaf04c---rakosujotaxew.pdfIn PDF document text
    • http://topas.lt/userfiles/file/ruzejukilapano.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160845e33f2e6b---mujikarawarelu.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea406dbced---kazutidazipupexi.pdfIn PDF document text
    • http://paillasse.hu/userfiles/file/lomaxikabi.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/qtfn96aa6kkif3pt6fe6a6c8lt/89236981995.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608fddee9beee---87555246809.pdfIn PDF document text
    • http://highendschmiede.de/highendfiles/file/xikapej.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/ppisca1cnsrmqccqsqpqs9dg57/bugop.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071546659ed0---9183933952.pdfIn PDF document text
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16083e09edd04d---pezedifilifuduxoxoxixosed.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f276319b94---34378926955.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/08p0blr9c7dtlqgstoc03u0mrq/44842880844.pdfIn PDF document text
    • http://datajournonepal.org/files/sukupovomenorumasagebile.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b19c050480e---42485624448.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071ec8b9d8cc---zutizo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eb85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB85 5648 bytes
SHA-256: c3d7f63bef0215538a65bee01e996ce18820e13f6d69a1d3eb65192e69e0577f
font_01_sfnt_off0000fe9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE9C 11004 bytes
SHA-256: 236a555bd2291425880d073a43a0464ff1fd7c558c74e94c97f048166ade7ef3