stay away from PuTTY!!
Antiviruses detected that their .exe was infected, and they solved it by removing the detection on the antiviruses
> 2015-04-19 PuTTY detected as malware
> We've had several reports recently of anti-virus software reporting PuTTY as malware (under a wide variety of names, often generic). This affects the latest release (0.64) and also the development snapshots (particularly puttygen).
> We believe these are false positives. In those cases where we've been able to contact the vendor (McAfee, Symantec, ClamAV), they have removed the detection.