Before you download or install programs, you should follow four steps.
Step one
Check the issuer and the affiliation of the certificates for signed programs. Accept downloads only from people you trust - not from untrustworthy websites or websites you do not know.
Step two
Do not open programs or files directly from a website. Save them on your hard disk first and check for viruses manually if your antivirus program does not do so automatically.
Step three
When you have saved, check that the file name is unchanged and that the file did not become a program. Files ending with “.exe”, “.bat”, “.cpm”, “.vbs” or “.pif” are program files.
Step four
When satisfied on all counts, open the file. Avoid double-clicking on the file. Instead, open the file in the program in which the file appears to have been created.