JACKSONVILLE, Fla. -

Tens or even hundreds of thousands of computer users could be unable to get online this summer.

The FBI is warning all computer owners to check for a type of malware, called "DNS Changer," similar to a virus.

PCs infected with DNS Changer were used by a group of hackers for fraud.

Federal agents say they've caught those responsible.

But a temporary solution keeping the infected machines on-line will go away in July, and users won't be able to connect to the internet.

You can check your computer by visiting FBI.gov finding DNS changer.