The Nasdaq composite index rose 12.93 to close at 3,720.24, and the Standard & Poor's 500 index dropped 5.72 to 1,409.38. Volume on the Nasdaq was 1.27 billion shares, its lowest daily trading volume in history. All four trading days this week made the Nasdaq's top 10 list for lowest daily volumes.
The Dow Jones industrial average fell 67.64 to 10,412.49, led by Wal-Mart and McDonald's.
The government will issue a report on employment tomorrow. If job creation or wages rise more than expected, the Federal Reserve could raise interest rates by at least a quarter-point later this month.
Intel edged up 50 cents to $119.56, while Microsoft slipped 13 cents to $70.44. A virus that spreads via the software maker's products struck millions of computers around the world.
The CNET tech index lost 7.74 to 2,909.76, as 53 of the 99 stocks in the index rose, 44 fell and two remained unchanged.
Of the 18 sectors tracked, computer memory storage companies gained the most, rising 4 percent. Server hardware makers were the largest losers, falling nearly 2 percent.
Among members of the CNET tech index, Siebel Systems and VoiceStream Wireless posted strong gains, rising about 8 percent and 9 percent, respectively. Siebel climbed $9.94 to $130.44, while VoiceStream moved up $9 to $109.63.
Siebel posted a volume of almost 40 million shares, more than nine times the stock's daily average, which made it the second most-actively traded company on the Nasdaq Stock Market behind Cisco Systems.
Lexmark International Group and Knight/Trimark were among the losers in the index. Lexmark fell $6.94 to $101.13, and Knight/Trimark dropped $1.94 to $33.
The Philadelphia semiconductor index gained 17.33 to 1,087.66, led by chip equipment maker Novellus, which rose $3.06 to $64.
Analysts say that the virus sweeping through computer systems will likely be the most costly yet and could put new pressure on software companies to address code-writing techniques that have led to persistent security problems.
Sun Microsystems unveiled a corporate structure designed to improve quality and focus on customer demand. The technology giant's divisions will be grouped by the functions they perform, such as sales or services, rather than products they produce. Sun closed down $1.75 at $85.63.