You can add Advertiser Server IP to protect yourself from fraud, once you have added the IP list then if any conversion coming from any other IP will be automatically cancelled.
To update the Setting, from Side Menu go to Advertiser > Manage > Particular Advertiser > Settings > Basic.
In Basic > Conversion Tracking Card > Add list of IP (you will get from Advertiser). You can add following type of IP values.
- Single IP: 126.96.36.199
- Multiple Ip: 188.8.131.52
- IP Range: 184.108.40.206/26