Microsoft's CEO Steve Ballmer has confessed that his thought as he was attacked by an egg-hurling student in Hungary was to keep his suit clean.

The video of the bizarre attack on Ballmer – which took place in a Budapest University – has become an instant smash hit on the internet.

"I thought it was a joke... maybe some prank, some theatre from the university. Then I heard a sound -- Boom! And I looked at the board behind me, and I said 'uh oh, I have a problem'," Ballmer told Reuters.

"I thought, 'I have to keep this suit clean' so I ducked under the table because I was worried, egg doesn't clean off very easily."

Ballmer doesn't hold a grudge against the student, who was reportedly protesting about a government tender that was nothing to do with Microsoft.

"Oh, he waved to me on the way out, and I waved back," Ballmer added.