COPMUTER SCIECNE // CRYPTOLOGY

ANSWER BOTH PLEASE

After infecting a system, some viruses take steps to cleanse the system of any (other) malware. That is, they remove any malware that has previously infected the system, apply security patches, update signature files, etc. 1. Why would it be in a virus writer's interest to protect a system from other malware? 2. Discuss some possible defenses against malware that includes such anti-malware provisions