A computer virus similar to the Stuxnet virus that attacked Iran's nuclear program has been identified.
Duqu, with a malicious code similar to Stuxnet, was discovered on computer systems of companies in Europe, the computer security firm Symantec said in a report issued Tuesday.
"Parts of Duqu are nearly identical to Stuxnet, but with a completely different purpose," Symantec said in its report. "Duqu is essentially the precursor to a future Stuxnet-like attack."
The report added that the creators of the Duqu program had access to the Stuxnet source code.
Stuxnet, the computer worm that some say has set back Iran's nuclear program by several months or years, affected some of Iran's computer systems and centrifuges used to enrich uranium after it was released last year. The New York Times reported that it was a joint project of Israel and the United States.
Iran had to replace 1,000 Stuxnet-damaged centrifuges at its main uranium enrichment plant at Natanz last year.
Duqu is designed to gather data such as keystrokes from computer systems that will help it to launch future attacks on the systems.