An attacker could access information, documents, and possibly executables through Google Desktop via flaws (XSS in particular) in Googles website. Google Desktop keeps a fairly sizable index and cache for rapid search that by default is unencrypted. This index contains an amazing amount of historical data: It retains previous versions of files, web-based email communications, browsing history, etc. The problem is that this data persists even after reasonable efforts of the average user to delete it from the file system.”]
Source: https://www.csoonline.com/article/2136267/on–mis-trusting-google-desktop.html