AntiSniff v1.021 – Antisniff is Windows software which will detect if any sniffers are running on the network. Works on Win 95, 98, and NT, but not Win2k.
You can download it from the following link: https://packetstormsecurity.com/files/download/21877/as-1021.zip
Source: https://packetstormsecurity.com/files/21877/as-1021.zip.html