isc.sans.edu 3/2/2026, 11:38:53 AM · via preferred

RTF hides embedded ZIPs in OLE objects; URLs found via oledump

RTF hides embedded ZIPs in OLE objects; URLs found via oledump
CyberSIXT Evidence Panel Source marked as original reporting

THE SANS ISC diary explains how ZIP files can be embedded inside an RTF document, using OLE objects that can be analysed with oledump[.]py. It notes that options --storages and -E %CLSID% reveal the abused CLSID, and that the Stream CONTENTS can contain the URL, which was extracted using the method from a previous diary entry. The post also points out that the OLE object includes a .docx file, which is itself a ZIP container, and can be inspected with zipdump[.]py to uncover its contents.

A key detail is the ZIP file’s magic number, 50 4B 03 04, used to locate embedded ZIPs within the RTF; search results can then be used to extract URLs. This guidance was published on 2 March 2026 and is attributed to Didier Stevens. according to Didier Stevens.

View full article

Article by CyberSIXT