1 Stress echocardiogram: This is an echocardiogram that is performed while the person exercises on a treadmill or stationary bicycle. 2  This test can be used to visualize the motion of the heart's walls and pumping action when the heart is stressed.
Viruses require an active host program to cause damage and infect other executable files or documents, while worms are stand-alone malicious programs that can self-replicate and propagate via computer networks, without human help.
The worldwide web is the main source of malware. Malware can penetrate your computer as a result of the following actions: 1  Visiting a website that contains a malicious code. Drive-by attacks can be taken as an example. 2  A drive-by attack is carried out in two steps.