1.   Clicking on the attachment will launch the malicious program.

2.   In some cases, the malicious programs systematically falsify the network addresses from which the data is sent.

3.   It does not warn the user that the document in question could be a malicious program.

4.   The very fact that such malicious programs were commonplace indicates that few of us took their perils seriously.

5.   Those who study viruses say a change in the nature of personal computing has created a fertile environment for the spread of new, virulent and complex malicious programs.

6.   Though attachments to messages frequently contain malicious programs, these are easily destroyed by anti-virus programs that can be set to kick into action whenever attached documents are opened.

7.   Tuesday an administration official said that despite the fact that no widespread attacks were expected there is still concern about the potential for damage from malicious programs.

8.   The malicious program also leaves a virtual door open to further hacker attacks on the computer.

9.   Viruses are malicious programs that spread through networks and cause damage to data and programs stored in computers.