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.
Remove this template when most of the Wikipedia content has been removed or the Wikipedia information is outnumbered by non-Wikipedia information. Backdoor.Win32.IRCBot is a backdoor computer worm that spreads through MSN Messenger and Windows Live Messenger. Once installed on a PC the worm copies itself into a Windows system folder, creates a new file displayed as Windows Genuine Advantage Validation Notification and becomes part of the computer's automatic startup.