Microsoft and Rob McKenna, the Attorney General for the State of Washington, have filed lawsuits against Secure Computer from New York State and several unnamed individuals.

Secure Computer is accused of using deceptive advertising to sell its $49.95 Spyware Cleaner software. 

Users are presented with pop-up ads, search engine ads or spam emails offering a free online spyware scan of their hard drives.

The software then labels innocuous system files as 'high risk spyware' and advises consumers to buy the software to remove the pest.

The case is first in Washington State to be filed under a local anti-spyware law. If found guilty, Secure Computer could be fined up to $100,000 per violation.

Microsoft has assisted the attorney general in researching the case by providing technical assistance.

The company is charging Secure Computer with violating its trademarks to falsely suggest that Microsoft sponsored or approved the Spyware Cleaner software.

Microsoft urged computer owners to use a firewall, install updates and use antivirus and anti-spyware software.