Which malicious program cannot do anything until actions are taken to activate the file attached by the malware? 

Virus
A virus, also known as a computer virus, is a malicious program that cannot do anything until actions are taken to activate the file attached by the malware.

A Virus is a type of malware that can covertly transmit itself between computers via networks (especially the Internet) or removable storage devices such as disk and drives, often causing damage to the system and data.

If the file hosting the virus is not launched, the virus remains dormant and also spread by replicating itself to affect other files. It can also modify other computer programs.

One of the most dangerous viruses ever created is “ILOVEYOU.” It was created by Reonel Ramones and Onel de Guzman, who are Filipino programmers. The virus infected the computer via emails. This affected about 10 million computers in the space of 10 days.

A virus is a malicious program that cannot do anything until actions are taken to activate the file attached by the malware. At times, one of the major ways to differentiate between viruses and other malware such as worms is mostly the ability of worms to self-replicate themselves without necessarily getting themselves attached to their host before they can be activated, while viruses need to first attach to their host before they can do anything.What this means is that worms do not require any activation, while viruses need to be activated.

Mostly, files are usually infected with viruses when we download or share files. However, they will always remain dormant until the file hosting the virus is activated. What happens next is that the virus will begin to run and spread by infecting other files. The moment other files are affected and activated, they will keep running, and the malicious code will continue to spread.