Question: what are the most common symptoms of malware on a compromised system?
Answer: Slow computer. The most common symptom of a malware infection is a slow running computer. ...  Blue screen of death (BSOD) ...  Programs opening and closing automatically. ...  Lack of storage space. ...  Suspicious modem and hard drive activity. ...  Pop-ups, websites, toolbars and other unwanted programs. ...  You're sending out spam.