The hack spreading on Twitter Tuesday morning is extra nefarious...

The hack spreading on Twitter Tuesday morning is extra nefarious because the tweets activate without being clicked on — it’s enough for Web surfers to move their mouse cursors over them. (Sept. 3, 2010) Credit: AFP/Getty Images

A new way to cause mischief is spreading through short-messaging service Twitter as mysterious “tweets” of blocked-out text propagate themselves and cause popup windows to open.

The hack spreading Tuesday morning is extra nefarious because the tweets activate without being clicked on — it’s enough for Web surfers to move their mouse cursors over them.

However, the hack only affects visitors to Twitter.com. Various third-party programs used to send and read tweets appear to be unaffected.

The popups can contain malicious code that could take over poorly protected computers.

On the latest episode of "Sarra Sounds Off," Newsday's Gregg Sarra and Matt Lindsay take a look top boys and girls basketball players on Long Island. Credit: Newsday

Sarra Sounds Off, Ep. 15: LI's top basketball players On the latest episode of "Sarra Sounds Off," Newsday's Gregg Sarra and Matt Lindsay take a look top boys and girls basketball players on Long Island.

On the latest episode of "Sarra Sounds Off," Newsday's Gregg Sarra and Matt Lindsay take a look top boys and girls basketball players on Long Island. Credit: Newsday

Sarra Sounds Off, Ep. 15: LI's top basketball players On the latest episode of "Sarra Sounds Off," Newsday's Gregg Sarra and Matt Lindsay take a look top boys and girls basketball players on Long Island.

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