Direct action or non-resident viruses are file infectors designed to attach to executable files, such as .exe or .com files, and are activated whenever the infected file is run. A direct action virus actively seeks out and infects specific files or programs on a computer.Direct action viruses typically infect files in specific locations, such as the boot sector or system files, and may be activated when the infected file is opened or the infected computer is booted. The virus may also be activated when specific conditions are met, such as a specific date or time. A direct action virus can cause various problems, including deleting or corrupting files, slowing down or crashing the system and spreading to other computers on the same network.