If I leave it alone to my computer, would something bad happen to my computer?
The answer is YES. PUP.Optional.SpeedAnalysis3.A is extremely hazardous to your computer.
1) More and more system vulnerabilities can be created by PUP.Optional.SpeedAnalysis3.A. Then additional malicious files like Trojan, spyware, adware may use the vulnerabilities to get access to your computer. At that time, your computer firewall will be weaken and weaken.
2) Your computer will be largely slowed down and even caused system crash.