Keep in mind that a file's innocuous extension (*.txt, *.jpg, *.gif) does not necessarily mean that this file is what it claims to be. Check it with your anti-virus software.
We recommend the following software:
Anti-virus Software
Anti-virus software checks your system for the presence of viruses and deletes them if found.
A firewall is software that protects your system when it's connected to the Internet. Firewalls analyze all the data that enters and leaves your computer. It works as an invisible barrier that protects your computer from different types of attacks over the Internet.