Do you know how to determine if a piece of hostile software has successfully attacked your system?
One of the best ways to detect this is to scan your system with an up-to-date anti-virus scanner. Scanners examine your system for signs of hostile software activity, such as new or modified files, telltale database entries, and (in some cases) changed permissions.
You should also look for changes with your system that you cannot account for, such as new executables, changed permissions, or shares that have suddenly opened up. Other indications include high processor utilization with no open programs, constant network activity or odd behavior of the user interface.
There are many anti-virus product vendors doing a successful job detecting the effects of hostile software with their products. Contact me at 260.423.2414 or firstname.lastname@example.org for recommendations on anti-virus software.