Malvertisement - malware advertisement - is an infected online advertisement. These ads may be hosted in malicious as well as legitimate sites, and social networks. The use of infected ads allow cybercriminals to spread malware easily.
A memory-resident program has the ability to stay in the computer’s memory after execution and to continuously run. Typically backdoors stay in memory to await commands, as do . file infectors to infect files as they are opened.