List some common signs of malware infection.

Common signs of some malware infection include the following:

1. Frequent pop-up windows prompting us to visit some website and/or download some software.
2. Changes to the default homepage of web browser.
3. Mass emails being sent from our email account.
4. Unusually slow computer with frequent crashes.
5. Unknown programs startup as we turn on our computer.
6. Programs opening and closing automatically.
7. Sudden lack of storage space, random messages, sounds, or music start to appear.
8. Programs or files appear or disappear without our knowledge.