Police have arrested a Moroccan man and a Turkish man for allegedly spreading the Zotob worm, which affected a number of large firms this month.
Both men were arrested in their own countries after a joint investigation involving the US Federal Bureau of Investigation and Microsoft.
The Zotob worm, which caused PC outages, affected older Windows 2000 operating systems. The Financial Times, Caterpillar and Boeing were among those companies hit.
Zotob took advantage of a security flaw in the plug-and-play feature of Windows, and was spread just days after Microsoft issued a patch to correct the problem.