The client binaries and the launcher may be reported as computer viruses. It is a false positive. Our clients are based on well-known open-source software (IW4x and the launcher are open-source!).
We are not responsible for false detections from poorly made antivirus software. It is the responsibility of the antivirus vendor to avoid false detections.
It happens often when a new update is released, a new binary (exe) is unknown and it increases the likelihood of it being reported as a virus.