[@consuella] His comment did not help much because he did not mention the names of Trojans and viruses detected or antivirus software used to scan PC Services Optimizer installer.
Here is the virustotal.com report about servicesoptimizer.exe (MD5: 946408d5ea152f32e2d8818a872b41a6) installer used in this giveaway with 0% detection rate https://www.virustotal.com/#/file/d74a9554c1d556a1fa3d88ce86f875f211127813cb342cc774f15ad1ef122687/detection