the stdrt.exe has a relationship with Clickteam Fusion itself. In stdrt, we have "rt" for "runtime", it's the most important part of the software; so it's not a virus. Maybe you computer is infected with something else.
4 out of 65 antiviruses is very little, and I wouldn't be surprised if all 4 of them are completely unknown. I actually tried to scan the MF 4.4 installer with VirusTotal, and only 2 antiviruses detected anything - CMC and WhiteArmor. I've never heard of either of them before doing the scan.