(Boston, MA) -- Cyber attacks similar to the one that hit Target stores are reportedly underway against retailers across the U.S.

The security firm IntelCrawler said today it's tracking at least a half-dozen ongoing attempts to steal data.

The attacks involve the same type of malicious software used in the massive data breach at Target.

A company spokesman said IntelCrawler has alerted authorities, major banks and Visa about the threat.