TrendLabs has created a free STUXNET Scanner Tool to help administrators identify infected machines within their own networks. The tool enumerates live IP addresses within the internal network and sends spoofed packets similar to the packets sent by known STUXnet variants. Through this, network administrators can easily identify which IPs are infected within the network, thereby helping them perform the necessary actions to isolate and clean the said system. This is a Windows only tool and is only available for Windows users.
Source: https://thehackernews.com/2010/11/stuxnet-scanner-to-identify-stuxnet.html