By Jim Finkle

BOSTON, USA:  Malicious software that has infected millions of computers across the globe failed to wreak havoc on Wednesday as some feared, but researchers warned the powerful Conficker worm could still strike.

Also known as Downadup or Kido, Conficker turns infected PCs into slaves that respond to commands sent from a remote server that effectively controls an army of computers.

The fears of an attack, however, may have been a windfall for anti-virus software makers, who warned consumers about the worm, industry analysts say.

Symantec Corp, McAfee Inc and Trend Micro Inc spend millions of dollars a year on promotional campaigns that warn about threats to personal computers.

"A scare like this could make consumers think twice before deciding to let their subscriptions lapse," said FBR Capital Markets analyst Daniel Ives.

The industry had been under pressure because the recession caused some customers to hold off buying new software and others to delay renewing subscriptions.

Researchers feared the network created by Conficker might be deployed on Wednesday for the first time since the worm surfaced last year because it was programed to increase communication attempts with its master server from April 1.

The security industry formed a task force to fight the worm, bringing widespread attention that experts said probably scared off the criminals who command the army of slave computers, known as a botnet.

That group thwarted the worm partially by using the Internet's traffic control system to block access to servers that control the slave computers. But in cases where the slaves did connect, they did not receive new marching orders.

Researchers warned the botnet's commanders are probably waiting until they are under less scrutiny before they mobilize the network of infected computers.

"I never thought it would happen April 1," said Roger Thompson, chief research officer at AVG, an anti-virus firm. "It might be tomorrow. It might be next week. It might be next month."