The typical functions of droppers are transporting and installing viruses. They wait on the system for a specific event, at which point they launch themselves and infect the system with the contained virus. Related to these programs is the concept of the bomb. Bombs are usually built into malware as a means of activating it. Bombs are programmed to activate when a specific event occurs.
Some bombs activate at a specific time, typically using the system clock.
A bomb could be programmed to erase all DOC files from your hard disk on New Year's Eve or pop up a message on a famous person's birthday. Viewed this way, bombs are just malicious scripts or scheduling programs. Viruses can be thought of as special instances involving one or more of these malware programs. Find out how. ZDNet and ZDNet logo are registered trademarks of ZD Inc. Content originally published in Ziff Davis Media publications is the copyrighted property of Ziff Davis Media.